本文實例為大家分享了java實現(xiàn)銀行家算法的具體代碼,供大家參考,具體內(nèi)容如下
創(chuàng)新互聯(lián)建站是一家專注于成都網(wǎng)站設計、成都網(wǎng)站制作與策劃設計,綠春網(wǎng)站建設哪家好?創(chuàng)新互聯(lián)建站做網(wǎng)站,專注于網(wǎng)站建設十多年,網(wǎng)設計領域的專業(yè)建站公司;建站業(yè)務涵蓋:綠春等地區(qū)。綠春做網(wǎng)站價格咨詢:18980820575import java.util.Arrays; import javax.swing.JOptionPane; public class Banker_Dijkstra { static int available[]={3,3,2}; //可利用資源數(shù) static int max[][]={{7,5,3},{3,2,2},{9,0,2},{2,2,2},{4,3,3}};; //每線程大需求 static int allocation[][]={{0,1,0},{2,0,0},{3,0,2},{2,1,1},{0,0,2}}; //已分配資源 static int need[][]={{7,4,3},{1,2,2},{6,0,0},{0,1,1},{4,3,1}}; //需求 static int request[]=new int[3]; //存放請求資源 static int thread; //線程號 static JOptionPane jpane = new JOptionPane(); // static boolean m; public static void main(String[] argv){ int n = 0 ; Banker_Dijkstra bd = new Banker_Dijkstra(); for(int i=0;i<5;i++){ if(bd.safeState(i)){ JOptionPane.showMessageDialog(jpane, "系統(tǒng)狀態(tài)安全"); n=1; break; }else{ n=2; continue; } } if(n==1){ bd.getThread(); } else if(n==2){ JOptionPane.showMessageDialog(jpane, "系統(tǒng)狀態(tài)不安全"); } } protected void getThread(){//輸入測試線程號且輸出結(jié)果 try{ String xiancheng = JOptionPane.showInputDialog(jpane,"請輸入申請資源的線程:"); thread = (int) Integer.parseInt(xiancheng); }catch(Exception e){ int response = JOptionPane.showConfirmDialog(jpane, "請輸入0~4:",null, JOptionPane.YES_NO_OPTION); // 處理異常 if(response==0){ getThread(); }else if(response ==1){ System.exit(0); } } if(thread<0||thread>4){ JOptionPane.showMessageDialog(jpane, "請輸入0~4:"); getThread(); }else{ for(int i=0;i<3;i++){ String requestR = JOptionPane.showInputDialog(jpane,"請輸入申請的第"+(i+1)+"種資源(若不申請則填0)"); try{ request[i]=Integer.parseInt(requestR);} catch(Exception e){ JOptionPane.showConfirmDialog(jpane, "請輸入申請的第"+(i+1)+"種資源(若不申請則填0)",null,JOptionPane.YES_NO_OPTION); } } if(request[0]>need[thread][0]||request[1]>need[thread][1]||request[2]>need[thread][2]){ JOptionPane.showMessageDialog(jpane,thread+"線程申請的資源超出其需要的資源,請重新輸入"); getThread(); }else{ if(request[0]> available[0]||request[1]> available[1]||request[2]> available[2]){ JOptionPane.showMessageDialog(jpane,thread+"線程申請的資源大于系統(tǒng)資源,請重新輸入"); getThread(); } } // 分配資源 allocateData(thread); // 判斷 繼續(xù)模擬選擇與處理 int tag=0; if(check(thread)){ try{ String str = JOptionPane.showInputDialog(jpane,"是/否 繼續(xù)模擬?( 1/0 ):"); tag = Integer.parseInt(str); }catch(Exception e){ JOptionPane.showMessageDialog(jpane, "繼續(xù) 輸入(數(shù)值) 1,不繼續(xù) 輸入(數(shù)值) 0 !"); } if(tag==1){ recoverData(thread); getThread(); } else{ if( (JOptionPane.YES_NO_OPTION)==JOptionPane.CANCEL_OPTION)System.exit(0); if((JOptionPane.YES_NO_OPTION)==JOptionPane.YES_OPTION) recoverData(thread); } }else{ recoverData(thread); getThread(); } } } // 安全算法 private boolean check(int thread2) { boolean[] finish = new boolean[5]; Arrays.fill(finish, false); int[] work = new int[3]; int[] queue = new int[5]; int q=0;//安全序列下標 for(int i = 0;i<3;i++){ work[i] = available[i]; } int tT = thread2; while(tT<5){ for(int R=0;R<3;R++){ if((!(finish[tT]==false))||(!(work[R]>=need[tT][R]))){ tT++; break; }else{ if(R==2){ for(int m =0;m<3;m++){ work[m] += allocation[tT][m]; } for(int s:work){ System.out.print(s+" "); } System.out.println(""); finish[tT] = true; queue[q] = tT; q++; tT =0; } } } } for(int p =0;p<5;p++){ if(finish[p]==false){ JOptionPane.showMessageDialog(jpane, "安全序列生成失敗"); return false; } } JOptionPane.showMessageDialog(jpane, "安全序列:"+queue[0]+","+queue[1]+"," +queue[2]+","+queue[3]+","+queue[4]); return true; } private boolean safeState(int thread3){ boolean[] finish = new boolean[5]; Arrays.fill(finish, false); int[] work = new int[3]; int[] queue = new int[5]; int q=0;//安全序列下標 for(int i = 0;i<3;i++){ work[i] = available[i]; } int tT = thread3; while(tT<5){ for(int R=0;R<3;R++){ if((!(finish[tT]==false))||(!(work[R]>=need[tT][R]))){ tT++; break; } else{ if(R==2){ for(int m =0;m<3;m++){ work[m] += allocation[tT][m]; } finish[tT] = true; queue[q] = tT; q++; tT =0; } } // if((finish[tT]==false)&&(work[R]>=need[tT][R])){ // for(int m =0;m<3;m++){ // work[m] += allocation[tT][m];} // finish[tT] = true; // queue[q] = tT; // q++; // tT=0; // }else{ // tT++; // break; // } } } for(int p =0;p<5;p++){ if(finish[p]==false){ return false; } } return true; } private void recoverData(int thread2) { // 生成失敗則重置已分配資源 for(int i=0;i<3;i++){ //重新調(diào)整系統(tǒng)資源數(shù) available[i]+=request[i]; //計算各個線程擁有資源 allocation[thread2][i]-=request[i]; //重新計算需求 need[thread2][i]+=request[i]; } } private void allocateData(int thread2) { //分配 for(int i=0;i<3;i++){ //重新調(diào)整可用系統(tǒng)資源數(shù) available[i]-=request[i]; //計算各個線程分配后擁有資源 allocation[thread2][i]+=request[i]; //重新計算需求 need[thread2][i]-=request[i]; } } }
另外有需要云服務器可以了解下創(chuàng)新互聯(lián)建站www.cdcxhl.com,海內(nèi)外云服務器15元起步,三天無理由+7*72小時售后在線,公司持有idc許可證,提供“云服務器、裸金屬服務器、高防服務器、香港服務器、美國服務器、虛擬主機、免備案服務器”等云主機租用服務以及企業(yè)上云的綜合解決方案,具有“安全穩(wěn)定、簡單易用、服務可用性高、性價比高”等特點與優(yōu)勢,專為企業(yè)上云打造定制,能夠滿足用戶豐富、多元化的應用場景需求。