java==IO练习，文件切割合拼工具开发代码

package 递归;
/*
 * 1、递归一定要明确条件，否则容易栈内存溢出
 * 2、注意递归次数，次数太多容易造成栈内存溢出
 * */
public class DiGuiDemo {

    public static void main(String[] args) {
        //toBin(6);
        int sum = getSum(5);
        System.out.println(sum);

    }
    public static void toBin(int num){
        if(num>0){
            System.out.println(num%2);
            toBin(num/2);
        }
    }
    public static int getSum(int num){
        if(num==1)
            return 1;
        return num+getSum(num-1);
    }

}

package 文件切割合拼;

import java.io.File;
import java.io.FilenameFilter;

public class filByName implements FilenameFilter {
    private String x;
    public filByName(String x){
        super();
        this.x=x;
    }

    @Override
    public boolean accept(File dir, String name) {

        return name.endsWith(x);
    }

}

package 文件切割合拼;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

public class SplitFileDemo {
    public static final int SIZE = 1024*1024;

    public static void main(String[] args) throws IOException {
        File ff1 = new File("d:\linux.doc");

        splitFile_2(ff1);
        
    }

    public static void splitFile_2(File ff1) throws IOException {
        FileInputStream fis = new FileInputStream(ff1);
        byte[]buf = new byte[SIZE];
        int len =0 ;
        int count =0;
        File dir = new File("d:\filepart");
        if(!dir.exists()){
            dir.mkdirs();
        }
        FileOutputStream fos = null;
        while((len=fis.read(buf))!=-1){
            fos= new FileOutputStream(new File(dir,(count++)+".part"));
            fos.write(buf,0,len);
            fos.close();
        }
        Properties p = new Properties();
        FileOutputStream fos1 = new FileOutputStream(new File(dir,".Properties"));
        p.setProperty("filepart", count+"");
        p.setProperty("filename", ff1.getName());
        p.store(fos1, "file part info");
        fis.close();
        fos1.close();
    }

    public static void splitFile(File file) throws IOException {
        FileInputStream f1 = new FileInputStream(file); 
        byte[]buf = new byte[SIZE];
        FileOutputStream fo1 = null;
        int len = 0;
        int count=1;
        File dir = new File("d:\partfiles");
        if(!dir.exists()){
            dir.mkdirs();
        }
        while((len=f1.read(buf))!=-1){
            fo1 = new FileOutputStream(new File(dir,(count++)+".part"));
            fo1.write(buf,0,len);
        }
        f1.close();
        fo1.close();
    }

}

package 文件切割合拼;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.SequenceInputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Properties;

/**
 * 文件合拼：
 * 思路：
 * 1、过滤.properties读取配置信息，获取filepart，filename
 * 2、过滤.part,序列流读取.part文件
 * 3、写入指定磁盘文件夹中
 * */
public class MegerFileDemo {

    public static void main(String[] args) throws IOException {
        File dir = new File("d:\filepart");
        megerFile(dir);

    }
    public static void megerFile(File dir)throws IOException{
        
        File[]names = dir.listFiles(new filByName(".Properties"));
        File confile=names[0];
        if(names.length!=1){
            throw new RuntimeException("文件加载出错，请重新下载此文件再试");
        }
        Properties p = new Properties();
        FileInputStream fis = new FileInputStream(confile);
        p.load(fis);
        int count = Integer.parseInt(p.getProperty("filepart"));
        String name= p.getProperty("filename");
        File[]parts = dir.listFiles(new filByName(".part"));
        if(parts.length!=count){
            throw new RuntimeException("文件个数不对，请重新下载");
        }
        ArrayList<FileInputStream> arr1 = new ArrayList<FileInputStream>();
        for(int x=0;x<parts.length;x++){
            //file对象就含有文件路径，所以下面可以使用parts[x]代替new File(dir,(x+".part"))
            arr1.add( new FileInputStream(new File(dir,(x+".part"))));
        }
        Enumeration<FileInputStream> en =  Collections.enumeration(arr1);
        SequenceInputStream sis = new SequenceInputStream(en);
        FileOutputStream fos = new FileOutputStream(new File(dir,name));
        byte[]buf = new byte[1024*1024];
        int len= 0;
        while((len=sis.read(buf))!=-1){
            fos.write(buf, 0, len);
        }
        sis.close();
        fos.close();
    }

}