import java.io.File; 
import java.io.InputStream; 
import java.io.FileInputStream; 
import java.io.OutputStream; 
import java.io.FileOutputStream; 
import java.util.Properties; 
import java.util.Iterator; 
import java.util.TreeSet; 
import java.util.Set; 
 
public class Test 
{ 
  public static void main(String[] args) throws Exception 
  { 
    /* 
    *將一個文件分割為多個文件,然后再組合成一個文件 
    * 找到文件,讀入一個1M的buffer中,然后寫入一個Part文件中,循環(huán)此操作直到文件讀取完畢 
    */ 
 
    String sourceFilePath = "D:" + File.separator + "Code" + File.separator + "source" + File.separator + "031316_【第13章：Java類集】_屬性類：Properties.wmv"; 
    int partFileLength = 1024*1024;//指定分割的子文件大小為1M 
    splitFile(sourceFilePath,partFileLength);//將文件分割 
    combineFile("D:" + File.separator + "Code" + File.separator + "target");//將分割后的文件合并 
  } 
 
  public static void combineFile(String directoryPath) throws Exception 
  { 
    Properties config = new Properties(); 
    InputStream ips = null; 
    ips = new FileInputStream(new File(directoryPath + File.separator + "config.properties")); 
    config.load(ips); 
 
    Set keySet = config.keySet();//需要將keySet轉(zhuǎn)換為int型 
     
     
    //將keySet迭代出來,轉(zhuǎn)換成int類型的set,排序后存儲進去 
    Set<Integer> intSet = new TreeSet<Integer>(); 
    Iterator iterString = keySet.iterator(); 
    while(iterString.hasNext()) 
    { 
      String tempKey = (String)iterString.next(); 
      if("name".equals(tempKey)) 
      {} 
      else 
      { 
        int tempInt ; 
        tempInt = Integer.parseInt(tempKey); 
        intSet.add(tempInt); 
      } 
    } 
     
    Set<Integer> sortedKeySet = new TreeSet<Integer>(); 
    sortedKeySet.addAll(intSet); 
 
    OutputStream eachFileOutput = null; 
    eachFileOutput = new FileOutputStream(new File("D:" + File.separator + "Code" + File.separator + config.getProperty("name"))); 
 
    Iterator iter = sortedKeySet.iterator(); 
    while(iter.hasNext()) 
    { 
      String key = new String("" + iter.next()); 
      if(key.equals("name")) 
      {} 
      else 
      { 
        //System.out.println("debug---"); 
        String fileNumber = null; 
        String filePath = null; 
        fileNumber = key; 
        filePath = config.getProperty(fileNumber); 
 
        //循環(huán)讀取文件 --> 依次寫入 
 
        InputStream eachFileInput = null; 
         
        eachFileInput = new FileInputStream(new File(filePath)); 
         
        byte[] buffer = new byte[1024*1024*1];//緩沖區(qū)文件大小為1M 
        int len = 0; 
        while((len = eachFileInput.read(buffer,0,1024*1024*1)) != -1) 
        { 
          eachFileOutput.write(buffer,0,len); 
        } 
        eachFileInput.close(); 
      } 
    } 
 
    eachFileOutput.close(); 
  } 
 
  public static void splitFile(String sourceFilePath,int partFileLength) throws Exception  
  { 
    File sourceFile = null; 
    File targetFile = null; 
    InputStream ips = null; 
    OutputStream ops = null; 
    OutputStream configOps = null;//該文件流用于存儲文件分割后的相關(guān)信息，包括分割后的每個子文件的編號和路徑,以及未分割前文件名 
    Properties partInfo = null;//properties用于存儲文件分割的信息 
    byte[] buffer = null; 
    int partNumber = 1; 
    sourceFile = new File(sourceFilePath);//待分割文件 
    ips = new FileInputStream(sourceFile);//找到讀取源文件并獲取輸入流 
    configOps = new FileOutputStream(new File("D:" + File.separator + "Code" //配置文件 
      + File.separator + "target" + File.separator + "config.properties")); 
    buffer = new byte[partFileLength];//開辟緩存空間 
    int tempLength = 0; 
    partInfo = new Properties();//key:1開始自動編號 value:文件路徑 
 
    while((tempLength = ips.read(buffer,0,partFileLength)) != -1)  
    { 
      String targetFilePath = "D:" + File.separator + "Code"  
        + File.separator + "target" + File.separator + "part_" + (partNumber);//分割后的文件路徑+文件名 
      partInfo.setProperty((partNumber++)+"",targetFilePath);//將相關(guān)信息存儲進properties 
      targetFile = new File(targetFilePath); 
      ops = new FileOutputStream(targetFile);//分割后文件 
      ops.write(buffer,0,tempLength);//將信息寫入碎片文件 
 
      ops.close();//關(guān)閉碎片文件 
    } 
    partInfo.setProperty("name",sourceFile.getName());//存儲源文件名 
    partInfo.store(configOps,"ConfigFile");//將properties存儲進實體文件中 
    ips.close();//關(guān)閉源文件流 
  } 
}