一、MongoDB數(shù)據(jù)庫參數(shù)配置
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1、推薦使用mongodb.cfg.properties配置，則在構(gòu)造MongoDBService對象的時候只需調(diào)用無參構(gòu)造方法即可自動完成配置。
2、如果沒有通過mongodb.cfg.properties，會采用程序指定的默認(rèn)配置。
// 定義默認(rèn)配置，1、IP地址 2、端口號 3、用戶名 4、密碼 5、配置文件位置名 6、數(shù)據(jù)庫名????private static final String MONGODB_ADDRESS = "127.0.0.1";????private static final int MONGODB_PORT = 27017;????private static final String MONGODB_USERNAME = "root";????private static final String MONGODB_PASSWORD = "";????private static final String MONGODB_RESOURCE_FILE = "mongodb.cfg.properties";????private static final String MONGODB_DBNAME = "test";????private static final String MONGODB_COLLECTIONNAME = "test";
3、通過有參構(gòu)造方法構(gòu)造MongoDBService對象或通過get/set方法，指定數(shù)據(jù)庫及集合，優(yōu)先級最高。
//有參構(gòu)造方法，指定數(shù)據(jù)庫名與集合名????public MongoDBServiceImpl(String dbName, String collName) {????????this.dbName = dbName;????????this.collName = collName;????????try {????????????db = getDb();????????} catch (Throwable e) {????????????e.printStackTrace();????????}????}????//無參構(gòu)造方法，返回配置文件配置的數(shù)據(jù)庫對象引用，如果配置文件中沒有設(shè)置則返回默認(rèn)數(shù)據(jù)庫對象引用????public MongoDBServiceImpl() {????????getDb();????}????/*?????* 獲取數(shù)據(jù)庫對象，3種情況（優(yōu)先級從高到低）：span style="white-space: pre" /span *1、構(gòu)造方法指定2、配置文件指定3、默認(rèn)數(shù)據(jù)庫span style="white-space: pre" /span *（情況2、3在MongoDButil中設(shè)置）?????*/????public DB getDb() {????????if (this.db == null) {????????????if (this.dbName == null) {????????????????this.db = MongoDBUtil.getDB();????????????} else {????????????????this.db = MongoDBUtil.getDBByName(this.dbName);????????????}????????}????????return this.db;????}?????????/*?????* 獲取集合對象，3種情況（優(yōu)先級從高到低）：?????????*1、構(gòu)造方法指定2、配置文件指定3、默認(rèn)數(shù)據(jù)庫?????*（情況2、3在MongoDButil中設(shè)置）?????*/????public DBCollection getCollection() {????????if(this.collName != null){????????????return db.getCollection(this.collName);????????}????????else {????????????return MongoDBUtil.getDBCollection();????????}????}
二、方法簡介（具體實現(xiàn)參看MongoDBServiceImpl接口實現(xiàn)類）
1、獲取基本信息或?qū)ο?
(1)、獲取數(shù)據(jù)庫名： getDbName()
(2)、設(shè)置數(shù)據(jù)庫名（指定數(shù)據(jù)庫）： setDbName(String dbName)
(3)、獲取集合名： getCollName()
(4)、設(shè)置集合名（指定集合）： setCollName(String collName)
(5)、獲取數(shù)據(jù)庫對象： getDb()
2、數(shù)據(jù)插入方式：
(1)、插入單條數(shù)據(jù)： insert(DBObject obj)
(2)、插入多條數(shù)據(jù)： insertBatch(List?list)void
3、數(shù)據(jù)刪除方式：
(1)、刪除單條數(shù)據(jù)： delete(DBObject obj)
(2)、刪除多條數(shù)據(jù)： deleteBatch(List?list)
4、數(shù)量統(tǒng)計方式：
(1)、獲取集合中數(shù)據(jù)數(shù)量： getCollectionCount()
(2)、獲取符合條件的數(shù)據(jù)數(shù)量： getCount(DBObject obj)
5、查找數(shù)據(jù)：
(1)、查找所有數(shù)據(jù)： findAll()
(2)、查找符合條件的數(shù)據(jù)： find(DBObject obj)
(3)、查找符合條件的數(shù)據(jù)并排序： find(DBObject query, DBObject sort)
(4)、查找符合條件的指定數(shù)量的數(shù)據(jù)并排序：find(DBObject query, DBObject sort, int start, int limit)
(5)、由ID查找數(shù)據(jù)： getById(String id)
6、更新數(shù)據(jù)?：update(DBObject setFields, DBObject whereFields) void
7、打印List：?printListDBObj(List?list)
測試代碼：（@Test）
public class testMongoService {????//使用mongodb.cfg.properties中配置的數(shù)據(jù)庫與集合，如未指定，使用MongoDBUtil中默認(rèn)的數(shù)據(jù)庫與集合????MongoDBService mongoDBService1 = new MongoDBServiceImpl();?????????//測試插入數(shù)據(jù)????@Test????public void testInsert(){????????//數(shù)據(jù)一，包括用戶名、密碼，地址信息（省份、城市），愛好[…]????????BasicDBList dbList1 = new BasicDBList();????????dbList1.add("basketball");????????dbList1.add("music");????????dbList1.add("web");????????DBObject dbObject1 = new BasicDBObject("username","insert1")????????????.append("age", 18)????????????.append("address", new BasicDBObject("province","廣東").append("city", "廣州"))????????????.append("favourite", dbList1);????????//數(shù)據(jù)二????????BasicDBList dbList2 = new BasicDBList();????????dbList2.add("football");????????dbList2.add("music");????????DBObject dbObject2 = new BasicDBObject("username","insert2")????????????.append("age", 18)????????????.append("address", new BasicDBObject("province","陜西").append("city", "西安"))????????????.append("favourite", dbList2);????????//數(shù)據(jù)三????????BasicDBList dbList3 = new BasicDBList();????????dbList3.add("Linux");????????DBObject dbObject3 = new BasicDBObject("username","insert3")????????????.append("age", 18)????????????.append("address", new BasicDBObject("province","河北").append("city", "保定"))????????????.append("favourite", dbList3);????????//數(shù)據(jù)四????????BasicDBList dbList4 = new BasicDBList();????????dbList4.add("swim");????????dbList4.add("android");????????DBObject dbObject4 = new BasicDBObject("username","insert4")????????????.append("age", 18)????????????.append("address", new BasicDBObject("province","四川").append("city", "成都"))????????????.append("favourite", dbList4);????????//數(shù)據(jù)五????????DBObject dbObject5 = new BasicDBObject("username", "insert5")????????????.append("age", 28)????????????.append("address", new BasicDBObject("city", "杭州"));????????mongoDBService1.printListDBObj(mongoDBService1.findAll());????????System.out.println("——————————————————insert collection——————————————————");????????Listdbobject list = new ArrayListdbobject();????????list.add(dbObject1);????????list.add(dbObject2);????????list.add(dbObject3);????????list.add(dbObject5);????????mongoDBService1.insertBatch(list);????????System.out.println("——————————————————insert one——————————————————");????????mongoDBService1.insert(dbObject4);????????mongoDBService1.printListDBObj(mongoDBService1.findAll());????}?????????//測試查詢數(shù)據(jù)????@Test????public void testFind(){????????DBObject dbObject = new BasicDBObject("username","insert1");????????System.out.println("數(shù)量：" + mongoDBService1.getCollectionCount());????????System.out.println("username=java的數(shù)據(jù)數(shù)量：" + mongoDBService1.getCount(dbObject));????????System.out.println("——————————————————find all——————————————————");????????mongoDBService1.printListDBObj(mongoDBService1.findAll());????????System.out.println("——————————————————find obj——————————————————");????????mongoDBService1.printListDBObj(mongoDBService1.find(dbObject));????????System.out.println("——————————————————find sort——————————————————");????????mongoDBService1.printListDBObj(mongoDBService1.find(new BasicDBObject(), new BasicDBObject("age", 1)));????????System.out.println("——————————————————find sort limit——————————————————");????????mongoDBService1.printListDBObj(mongoDBService1.find(new BasicDBObject(), new BasicDBObject("age", 1), 1, 2));????}?????//測試數(shù)據(jù)更新????@Test????public void testUpdate(){????????BasicDBObject newDocument = new BasicDBObject("$set",new BasicDBObject("age",11));?????????????????????????BasicDBObject searchQuery = new BasicDBObject().append("username", "insert2");?????????????mongoDBService1.printListDBObj(mongoDBService1.find(searchQuery));????????System.out.println("——————————————————update——————————————————");????????mongoDBService1.update(newDocument, searchQuery);????????mongoDBService1.printListDBObj(mongoDBService1.find(searchQuery));????}?????????//測試數(shù)據(jù)刪除????@Test????public void testDelete(){????????DBObject dbObject1 = new BasicDBObject("username", "insert1");????????DBObject dbObject2 = new BasicDBObject("username", "insert2");????????DBObject dbObject3 = new BasicDBObject("username", "insert3");????????DBObject dbObject4 = new BasicDBObject("username", "insert4");????????DBObject dbObject5 = new BasicDBObject("username", "insert5");????????Listdbobject list = new ArrayListdbobject();????????list.add(dbObject1);????????list.add(dbObject2);????????list.add(dbObject3);????????list.add(dbObject4);????????mongoDBService1.printListDBObj(mongoDBService1.findAll());????????System.out.println("——————————————————delete list——————————————————");????????mongoDBService1.deleteBatch(list);????????System.out.println("——————————————————delete one——————————————————");????????mongoDBService1.delete(dbObject5);????????//System.out.println("——————————————————delete all——————————————————");????????//mongoDBService1.delete(new BasicDBObject());????????mongoDBService1.printListDBObj(mongoDBService1.findAll());????}}/dbobject/dbobject/dbobject/dbobject
測試結(jié)果：
源代碼：（完整項目文件下載鏈接：點擊打開鏈接）
MongoDBServiceImpl.java
public class MongoDBServiceImpl implements MongoDBService {????private String dbName;????private String collName;????private DB db;?????????//有參構(gòu)造方法，指定數(shù)據(jù)庫名與集合名????public MongoDBServiceImpl(String dbName, String collName) {????????this.dbName = dbName;????????this.collName = collName;????????try {????????????db = getDb();????????} catch (Throwable e) {????????????e.printStackTrace();????????}????}????//無參構(gòu)造方法，返回配置文件配置的數(shù)據(jù)庫對象引用，如果配置文件中沒有設(shè)置則返回默認(rèn)數(shù)據(jù)庫對象引用????public MongoDBServiceImpl() {????????getDb();????}????/*?????* 獲取數(shù)據(jù)庫對象，3種情況（優(yōu)先級從高到低）：?????*1、構(gòu)造方法指定2、配置文件指定3、默認(rèn)數(shù)據(jù)庫?????*（情況2、3在MongoDButil中設(shè)置）?????*/????public DB getDb() {????????if (this.db == null) {????????????if (this.dbName == null) {????????????????this.db = MongoDBUtil.getDB();????????????} else {????????????????this.db = MongoDBUtil.getDBByName(this.dbName);????????????}????????}????????return this.db;????}?????????/*?????* 獲取集合對象，3種情況（優(yōu)先級從高到低）：?????*1、構(gòu)造方法指定2、配置文件指定3、默認(rèn)數(shù)據(jù)庫?????*（情況2、3在MongoDButil中設(shè)置）?????*/????public DBCollection getCollection() {????????if(this.collName != null){????????????return db.getCollection(this.collName);????????}????????else {????????????return MongoDBUtil.getDBCollection();????????}????}?????public DBObject map2Obj(Mapstring, object="" map) {????????DBObject obj = new BasicDBObject();????????if (map.containsKey("class") map.get("class") instanceof Class)????????????map.remove("class");????????obj.putAll(map);????????return obj;????}????//插入數(shù)據(jù)????public void insert(DBObject obj) {????????getCollection().insert(obj);????}????//插入多條數(shù)據(jù)????public void insertBatch(Listdbobject list) {????????if (list == null || list.isEmpty()) {????????????return;????????}????????Listdbobject listDB = new ArrayListdbobject();????????for (int i = 0; i list.size(); i++) {????????????listDB.add(list.get(i));????????}????????getCollection().insert(listDB);????}????//刪除數(shù)據(jù)????public void delete(DBObject obj) {????????getCollection().remove(obj);????}????//刪除多條數(shù)據(jù)????public void deleteBatch(Listdbobject list) {????????if (list == null || list.isEmpty()) {????????????return;????????}????????for (int i = 0; i list.size(); i++) {????????????getCollection().remove(list.get(i));????????}????}????//獲取集合中的數(shù)據(jù)數(shù)量????public long getCollectionCount() {????????return getCollection().getCount();????}????//查找符合條件的數(shù)據(jù)數(shù)量????public long getCount(DBObject obj) {????????if (obj != null)????????????return getCollection().getCount(obj);????????return getCollectionCount();????}????//查找符合條件的數(shù)據(jù)????public Listdbobject find(DBObject obj) {????????DBCursor cur = getCollection().find(obj);????????return DBCursor2list(cur);????}?????????//查找符合條件的數(shù)據(jù)并排序????@Override????public Listdbobject find(DBObject query, DBObject sort) {????????DBCursor cur;????????if (query != null) {????????????cur = getCollection().find(query);????????} else {????????????cur = getCollection().find();????????}????????if (sort != null) {????????????cur.sort(sort);????????}????????return DBCursor2list(cur);????}?????//查找符合條件的數(shù)據(jù)并排序，規(guī)定數(shù)據(jù)個數(shù)????@Override????public Listdbobject find(DBObject query, DBObject sort, int start,????????????int limit) {????????DBCursor cur;????????if (query != null) {????????????cur = getCollection().find(query);????????} else {????????????cur = getCollection().find();????????}????????if (sort != null) {????????????cur.sort(sort);????????}????????if (start == 0) {????????????cur.batchSize(limit);????????} else {????????????cur.skip(start).limit(limit);????????}????????return DBCursor2list(cur);????}?????????//將DBCursor轉(zhuǎn)化為listdbobject????private Listdbobject DBCursor2list(DBCursor cur) {????????Listdbobject list = new ArrayListdbobject();????????if (cur != null) {????????????list = cur.toArray();????????}????????return list;????}?????//更新數(shù)據(jù)????public void update(DBObject setFields, DBObject whereFields) {????????getCollection().updateMulti(whereFields, setFields);????}????//查詢集合中所有數(shù)據(jù)????public Listdbobject findAll() {????????DBCursor cur = getCollection().find();????????Listdbobject list = new ArrayListdbobject();????????if (cur != null) {????????????list = cur.toArray();????????}????????return list;????}?????//由ID獲取數(shù)據(jù)????public DBObject getById(String id) {????????DBObject obj = new BasicDBObject();????????obj.put("_id", new ObjectId(id));????????DBObject result = getCollection().findOne(obj);????????return result;????}?????public String getDbName() {????????return dbName;????}?????public void setDbName(String dbName) {????????this.dbName = dbName;????????this.db = MongoDBUtil.getDBByName(this.dbName);????}?????public String getCollName() {????????return collName;????}?????public void setCollName(String collName) {????????this.collName = collName;????}????@Override????public void printListDBObj(Listdbobject list) {????????// TODO Auto-generated method stub????????for(DBObject dbObject: list){????????????System.out.println(dbObject);????????}????}???????}/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/dbobject/string,
MongoDBUtil.java
public class MongoDBUtil {????// 定義默認(rèn)配置，1、IP地址 2、端口號 3、用戶名 4、密碼 5、配置文件位置名 6、數(shù)據(jù)庫名????private static final String MONGODB_ADDRESS = "127.0.0.1";????private static final int MONGODB_PORT = 27017;????private static final String MONGODB_USERNAME = "root";????private static final String MONGODB_PASSWORD = "";????private static final String MONGODB_RESOURCE_FILE = "mongodb.cfg.properties";????private static final String MONGODB_DBNAME = "test";????private static final String MONGODB_COLLECTIONNAME = "test";????// 定義靜態(tài)變量，1、Mongo對象（代表數(shù)據(jù)庫連接）2、DB對象（代表數(shù)據(jù)庫）3、集合名4、數(shù)據(jù)庫相關(guān)配置映射集合5、已獲取的數(shù)據(jù)庫連接????private static Mongo mongo;????private static DB db;????private static DBCollection collection;????private static Mapstring, string="" cfgMap = new HashMapstring, string=""();????private static Hashtablestring, db="" mongoDBs = new Hashtablestring, db=""();?????/**?????* 初始化Mongo的數(shù)據(jù)庫?????*/????static {????????init();????}?????/**?????* 獲取配置文件中配置的DB對象?????*/????public static DB getDB() {????????return db;????}?????/**?????* 獲取配置文件中配置的DBCollection對象?????*/????public static DBCollection getDBCollection() {????????return collection;????}?????/**?????* 根據(jù)數(shù)據(jù)庫名稱,得到數(shù)據(jù)庫 如果不存在,則創(chuàng)建一個該名稱的數(shù)據(jù)庫,并設(shè)置用戶名和密碼為配置文件中的參數(shù)值?????*?????* @param dbName?????* @return DB?????*/????@SuppressWarnings("deprecation")????public static DB getDBByName(String dbName) {????????DB db = mongo.getDB(dbName);????????if (!mongoDBs.contains(db)) {????????????System.out.println("add");????????????db.addUser(cfgMap.get("mongo.db.username"),????????????????????cfgMap.get("mongo.db.password").toCharArray());????????????mongoDBs.put(dbName, db);????????}????????return db;????}?????// ————————————————————————————————————初始化過程————————————————————————————————————????/**?????* 獲取配置文件mongedb.cfg.properties的文件對象?????*/????public static File getConfigFile() {????????String path = MongoDBUtil.class.getResource("/").getPath();????????String fileName = path + MONGODB_RESOURCE_FILE;????????System.out.println(fileName);????????File file = new File(fileName);????????if (file.exists()) {????????????return file;????????}????????return null;????}?????/**?????* 通過mongedb.cfg.properties配置文件初始化配置映射集合，如果沒有編寫配置文件，則加載程序指定的默認(rèn)配置?????*/????@SuppressWarnings("unchecked")????private static void initCfgMap() {????????File file = getConfigFile();????????if (file != null) {????????????Properties p = new Properties();????????????try {????????????????p.load(new FileInputStream(file));????????????????for (Enumeration enu = p.propertyNames(); enu.hasMoreElements();) {????????????????????String key = (String) enu.nextElement();????????????????????String value = (String) p.getProperty(key);????????????????????cfgMap.put(key, value);????????????????}????????????} catch (IOException e) {????????????????System.out.println("加載Mongo配置文件失敗!");????????????????e.printStackTrace();????????????}????????} else { // 如果沒有編寫配置文件，則加載默認(rèn)配置????????????cfgMap.put("mongo.db.address", MONGODB_ADDRESS);????????????cfgMap.put("mongo.db.port", String.valueOf(MONGODB_PORT));????????????cfgMap.put("mongo.db.username", MONGODB_USERNAME);????????????cfgMap.put("mongo.db.password", MONGODB_PASSWORD);????????????cfgMap.put("mongo.db.dbname", MONGODB_DBNAME);????????????cfgMap.put("mongo.db.collectionname", MONGODB_COLLECTIONNAME);????????}????}?????/**?????* 初始化Mongo的數(shù)據(jù)庫（將db指向相應(yīng)對象引用，將collection指向相應(yīng)對象引用，通過mongoDBs記錄現(xiàn)有數(shù)據(jù)庫對象）?????*/????@SuppressWarnings("deprecation")????private static void init() {????????initCfgMap();????????try {????????????String address = cfgMap.get("mongo.db.address");????????????int port = Integer.parseInt(cfgMap.get("mongo.db.port").toString());????????????String dbName = cfgMap.get("mongo.db.dbname");????????????String username = cfgMap.get("mongo.db.username");????????????String password = cfgMap.get("mongo.db.password");????????????String collectionName = cfgMap.get("mongo.db.collectionname");????????????mongo = new Mongo(address, port);????????????if (dbName != null !"".equals(dbName)) {????????????????db = mongo.getDB(dbName);????????????????if (username != null !"".equals(username)) {????????????????????db.addUser(username, password.toCharArray());????????????????????if (collectionName != null !"".equals(collectionName)) {????????????????????????collection = db.getCollection(collectionName);????????????????????}????????????????}????????????????mongoDBs.put(dbName, db);????????????}????????} catch (Exception e) {????????????e.printStackTrace();????????}????}?}
首先你得確定你的數(shù)據(jù)庫連接是通過什么形式連接的，hibernate還是原生態(tài)的jdbc 還是spring；
如果是只有hibernate，那么你得通過加載配置文件得到sessionFactory,然后得到session
如果spring，那么同樣也需要注入sessionfactory到你的dao
如果是jdbc方式，那么你就按照原生態(tài)jdbc寫法
總之，在你構(gòu)造DAO時，得有數(shù)據(jù)源。這樣才能操縱你的數(shù)據(jù)庫
如果搞懂了這些問題，那么你的第一個，第三個問題就迎刃而解了。至于第二問題，我沒明白你什么意思！
看一下--------SubjectAction
public String deleteSubject(){
isubjectbiz.deleteSubject(subjectId);
return SUCCESS;
}
subjectId 是否是用struts2 自動從頁面封裝過來的 還是你使用request獲取的 首先你輸出一下有沒有值 然后如果是request獲取的 必須要把它轉(zhuǎn)換成integer 其次如果有值 且為integer 這時你就要檢查你的數(shù)據(jù)庫隱射文件是否正確 一級一級排除
package org.dao;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.util.Date;
import org.dbc.DBManageer;
import org.dbc.DBUtil;
import org.vo.CardInfo;
public class CardInfoDao {
public void testResultSetMetaData() {
String sql = "select * from cardinfo";
Connection con = new DBUtil().getConnection();
PreparedStatement ps = null;
ResultSetMetaData rsmd = null;
ResultSet rs = null;
try {
ps = con.prepareStatement(sql);
rs = ps.executeQuery();
rsmd = rs.getMetaData();
for (int i = 1; i rsmd.getColumnCount(); i++) {
System.out.print(" 數(shù)據(jù)類型名:" + rsmd.getColumnClassName(i));
System.out.print(" 別名:" + rsmd.getColumnLabel(i));
System.out.print(" 列名:" + rsmd.getColumnName(i));
System.out.print(" 數(shù)據(jù)類型:" + rsmd.getColumnTypeName(i));
System.out.println(" 數(shù)據(jù)類型:" + rsmd.getColumnType(i));
}
while (rs.next()) {
// 通過反射可以對VO對象(CardInfo)自動賦值
// for(...)
// CardInfo ci=new CardInfo();
// ci.setId(rs.getInt(columnIndex))
/*
* CardInfo ca = new CardInfo(); Class cc = ca.getClass();
*/
/*Class? c = Class.forName("org.vo.CardInfo");
CardInfo ca = (CardInfo) c.newInstance();
ca.setCardId(rs.getString("cardId"));
ca.setCustomerName(rs.getString("customerName"));
ca.setCurrentMoney(rs.getFloat("currentMoney"));
ca.setOpenDate(rs.getDate("openDate"));
System.out.println(ca);//ok */
//加載一個CardInfo類
Class c = Class.forName("org.vo.CardInfo");
Object o = c.newInstance(); //獲得它的一個實例
//定義String類的對象數(shù)組
Class[] params = new Class[] { String.class};
//定義float類的對象數(shù)組
Class[] floatparams = new Class[] { float.class};
//定義Date(util)類的對象數(shù)組
Class[] dateparams = new Class[] { Date.class};
//獲得setCardId方法
Method me = c.getMethod("setCardId", params);
//實例方法的參數(shù)
Object []ostr = new Object[]{rs.getString("cardId")};
//如果底層方法是靜態(tài)的，那么可以忽略指定的 obj 參數(shù)。該參數(shù)可以為 null。
//如果底層方法所需的形參數(shù)為 0，則所提供的 args 數(shù)組長度可以為 0 或 null。
//o 調(diào)用方法的對象 ostr 方法調(diào)用的參數(shù)
me.invoke(o, ostr);
//獲得setCustomerName方法
Method name = c.getMethod("setCustomerName", params);
Object []cusname = new Object[]{rs.getString("customerName")};
name.invoke(o,cusname);
//獲得setCurrentMoney方法
Method money = c.getMethod("setCurrentMoney", floatparams);
Object []cusmoney = new Object[]{rs.getFloat("currentMoney")};
money.invoke(o,cusmoney);
//獲得setOpenDate方法
Method date = c.getMethod("setOpenDate",dateparams);
Object []openDate = new Object[]{rs.getDate("openDate")};
date.invoke(o, openDate);
//打印
System.out.println(o);
}
} catch (SQLException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
}catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
public void showResultSet() {
String sql = "select * from cardinfo";
Connection con = new DBManageer().getConnection();
PreparedStatement ps = null;
try {
ps = con.prepareStatement(sql, ResultSet.TYPE_SCROLL_SENSITIVE,
ResultSet.CONCUR_UPDATABLE);
ResultSet rs = ps.executeQuery();
System.out.println("---依次讀取------");
while (rs.next()) {
CardInfo ca = new CardInfo();
ca.setCardId(rs.getString("cardId"));
ca.setCustomerName(rs.getString("customerName"));
ca.setCurrentMoney(rs.getFloat("currentMoney"));
ca.setOpenDate(rs.getDate("openDate"));
System.out.println(ca);
}
System.out.println("---倒讀------");
while (rs.previous()) {
CardInfo ca = new CardInfo();
ca.setCardId(rs.getString("cardId"));
ca.setCustomerName(rs.getString("customerName"));
ca.setCurrentMoney(rs.getFloat("currentMoney"));
ca.setOpenDate(rs.getDate("openDate"));
System.out.println(ca);
}
rs.absolute(3);// 定位倒第幾行
rs.updateString("customerName", "star");
// rs.updateRow();
rs.beforeFirst();
while (rs.next()) {
CardInfo ca = new CardInfo();
ca.setCardId(rs.getString("cardId"));
ca.setCustomerName(rs.getString("customerName"));
ca.setCurrentMoney(rs.getFloat("currentMoney"));
ca.setOpenDate(rs.getDate("openDate"));
System.out.println(ca);
}
} catch (SQLException e) {
e.printStackTrace();
}
}
}
連接數(shù)據(jù)庫
public class DBManager {
//定義數(shù)據(jù)庫連接的URL
private static final String URL="jdbc:sqlserver://localhost:1433;database=j1105";
//定義數(shù)據(jù)庫的用戶名
private static final String USERNAME = "sa";
//定義數(shù)據(jù)庫密碼
private static final String PASSWORD = "sa";
//定義一個連接的引用,使用單例模式
private static Connection conn = null;
//使用靜態(tài)塊來注冊驅(qū)動
//類加載時自動執(zhí)行代碼塊
static {
//反射com.microsoft.sqlserver.jdbc.SQLServerDriver.class
try {
Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
//獲得連接
//在程序使用過程中始終只有1個對象存在
//使用單例模式來給Connection賦值
public static Connection getConnection(){
if(conn == null){
try {
conn = DriverManager.getConnection(URL, USERNAME, PASSWORD);
} catch (SQLException e) {
e.printStackTrace();
}
}
return conn;
}
/**
* 關(guān)閉的一些操作 , 優(yōu)化
* @param conn
* @param stat
* @param rs
*/
public static void close(Connection conn,Statement stat,ResultSet rs){
try{
if(conn != null){
conn.close();
}
if(stat != null){
stat.close();
}
if(rs != null){
rs.close();
}
}catch(SQLException e){
e.printStackTrace();
}
}
/**
* 重寫上面的方法,在只有2個參數(shù)的情況下關(guān)閉
* @param conn
* @param stat
*/
public static void close(Connection conn,Statement stat){
try{
if(conn != null){
conn.close();
}
if(stat != null){
stat.close();
}
}catch(SQLException e){
e.printStackTrace();
}
}
public static void main(String[] args){
Connection conn = DBManager .getConnection();
System.out.println(conn);
}
}
接口
public interface IStudentDao {
public void deleteStudent(int xh);
}
實現(xiàn)
public class StudentDAOimpl implements IStudentDao {
public void deleteStudent(int xh) {
try{
String sql = "delete from tb_student where xh = ?";
PreparedStatement ps = conn.prepareStatement(sql);
ps.setInt(1, xh);
ps.executeUpdate();
System.out.println("成功刪除");
}catch(SQLException e){
e.printStackTrace();
}
}
}
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