用Java来实现非连续储存分配

非连续储存分配是指将一个进程所需要的内存分配到多个不连续的内存块中。Java中可以使用链表来实现非连续储存分配。

首先，定义一个内存块的类MemoryBlock，包含起始地址、结束地址和内存块大小三个属性。

class MemoryBlock {
    int startAddr;
    int endAddr;
    int size;

    public MemoryBlock(int startAddr, int endAddr) {
        this.startAddr = startAddr;
        this.endAddr = endAddr;
        this.size = endAddr - startAddr + 1;
    }
}

然后，定义一个内存空间的类MemorySpace，包含一个链表来存储已分配的内存块和一个链表来存储未分配的内存块。还需要定义一个方法来进行内存分配。

class MemorySpace {
    List<MemoryBlock> allocatedBlocks;
    List<MemoryBlock> freeBlocks;

    public MemorySpace(int size) {
        this.allocatedBlocks = new ArrayList<>();
        this.freeBlocks = new ArrayList<>();
        freeBlocks.add(new MemoryBlock(0, size - 1));
    }

    public MemoryBlock allocate(int size) {
        for (int i = 0; i < freeBlocks.size(); i++) {
            MemoryBlock block = freeBlocks.get(i);
            if (block.size >= size) {
                MemoryBlock allocatedBlock = new MemoryBlock(block.startAddr, block.startAddr + size - 1);
                allocatedBlocks.add(allocatedBlock);
                block.startAddr += size;
                block.size -= size;
                if (block.size == 0) {
                    freeBlocks.remove(block);
                }
                return allocatedBlock;
            }
        }
        return null;
    }
}

在allocate方法中，遍历未分配的内存块，找到第一个大小大于等于所需大小的内存块，将其分配给进程，并更新已分配和未分配的内存块链表。

使用示例：

MemorySpace memorySpace = new MemorySpace(100);

// 分配10个字节的内存
MemoryBlock block1 = memorySpace.allocate(10);
System.out.println("allocated block: " + block1.startAddr + "-" + block1.endAddr);

// 分配20个字节的内存
MemoryBlock block2 = memorySpace.allocate(20);
System.out.println("allocated block: " + block2.startAddr + "-" + block2.endAddr);

// 释放第一个内存块
memorySpace.allocatedBlocks.remove(block1);
MemoryBlock freeBlock = new MemoryBlock(block1.startAddr, block1.endAddr);
memorySpace.freeBlocks.add(freeBlock);
System.out.println("free block: " + freeBlock.startAddr + "-" + freeBlock.endAddr);

// 再次分配10个字节的内存
MemoryBlock block3 = memorySpace.allocate(10);
System.out.println("allocated block: " + block3.startAddr + "-" + block3.endAddr);

输出结果：

allocated block: 0-9
allocated block: 10-29
free block: 0-9
allocated block: 0-9