基于Java写一个死锁避免银行家算法

银行家算法是一种资源分配和避免死锁的经典算法，下面是基于Java实现的示例代码：

public class BankerAlgorithm {

    private int[][] need; // 进程还需要的资源
    private int[][] allocation; // 进程已经拥有的资源
    private int[] available; // 系统剩余的资源
    private int[][] max; // 进程最大需求资源
    private int[] work; // 可用资源

    private int processNum; // 进程数量
    private int resourceNum; // 资源种类数量

    private boolean[] finish; // 进程是否运行完成

    public BankerAlgorithm(int[][] need, int[][] allocation, int[] available, int[][] max) {
        this.need = need;
        this.allocation = allocation;
        this.available = available;
        this.max = max;

        this.processNum = need.length;
        this.resourceNum = available.length;

        this.work = Arrays.copyOf(available, resourceNum);
        this.finish = new boolean[processNum];
    }

    /**
     * 检查当前状态是否安全
     */
    public boolean isSafe() {
        int count = 0;
        int[] safeSequence = new int[processNum];

        while (count < processNum) {
            boolean flag = false;

            for (int i = 0; i < processNum; i++) {
                if (!finish[i]) {
                    int j;
                    for (j = 0; j < resourceNum; j++) {
                        if (need[i][j] > work[j]) {
                            break;
                        }
                    }

                    if (j == resourceNum) {
                        for (int k = 0; k < resourceNum; k++) {
                            work[k] += allocation[i][k];
                        }

                        safeSequence[count++] = i;
                        finish[i] = true;
                        flag = true;
                    }
                }
            }

            if (!flag) {
                return false;
            }
        }

        System.out.print("Safe sequence: ");
        for (int i = 0; i < processNum; i++) {
            System.out.print(safeSequence[i] + " ");
        }
        System.out.println();

        return true;
    }

    /**
     * 分配资源给进程
     */
    public boolean allocate(int processId, int[] request) {
        for (int i = 0; i < resourceNum; i++) {
            if (request[i] > need[processId][i] || request[i] > available[i]) {
                return false;
            }
        }

        for (int i = 0; i < resourceNum; i++) {
            available[i] -= request[i];
            allocation[processId][i] += request[i];
            need[processId][i] -= request[i];
        }

        return true;
    }

    /**
     * 释放已分配资源
     */
    public boolean release(int processId, int[] release) {
        for (int i = 0; i < resourceNum; i++) {
            if (release[i] > allocation[processId][i]) {
                return false;
            }
        }

        for (int i = 0; i < resourceNum; i++) {
            available[i] += release[i];
            allocation[processId][i] -= release[i];
            need[processId][i] += release[i];
        }

        return true;
    }
}

BankerAlgorithm类中包含了资源分配和避免死锁的方法，其中isSafe()方法可以检查当前状态是否安全，allocate()方法可以分配资源给进程，release()方法可以释放已分配资源。可以根据具体的业务场景进行调用。