黑馬程式員_<<properties,列印流，合并流，分割流>>

1. Properties         1.概述

        2.常用方法

      

 public class PropertiesDemo1 {   public static void main(String[] args) {     Properties pro = new Properties();     /* setProperty(String key,String value)添加鍵和值 */     pro.setProperty("java01", "001");     pro.setProperty("java02", "002");     /* 通過鍵獲得值：String getProperty(String key) */     System.out.println(pro.getProperty("java01"));     /* Set<String>stringPropertyNames()獲得鍵集 */     Set<String> set = pro.stringPropertyNames();     for (String s : set)        System.out.println(s + ":" + pro.getProperty(s));   } }結果：001java02:002java01:001

            3.設定檔

import java.io.FileReader;import java.io.IOException;import java.util.HashMap;import java.util.Properties;import java.util.Set; public class PropertiesDemo1 {   public static void main(String[] args) throws IOException {     BufferedReader br = new BufferedReader(new FileReader("F:\\pro.txt"));//讀取流     HashMap<String, String> map = new HashMap<String, String>();//map集合     String line = null;     while ((line = br.readLine()) != null) {        String[] s = line.split("=");        map.put(s[0], s[1]);     }     System.out.println(map);   } }結果：{java02=002, java03=003, java01=001}

 

import java.io.FileReader;import java.io.FileWriter;import java.io.IOException;import java.util.HashMap;import java.util.Properties;import java.util.Set; public class PropertiesDemo1 {   public static void main(String[] args) throws IOException {     /* void load(Reader reader)將讀取流字元流載入到集合中 */     Properties pro = new Properties();     FileReader fr = new FileReader("F:\\pro.txt");     pro.load(fr);// 將字元讀取流中讀取的檔案放到Properties對象中     System.out.println("載入後的集合：" + pro);     /* 下面我們修改集合中的數值 */     pro.setProperty("java02", "hello");     /*      * store(Writer writer,String      * comments)通過字元寫入流，把集合中的資訊更新設定檔，comments是注視內容      */     FileWriter fw = new FileWriter("F:\\pro.txt");     pro.store(fw, "java");// 更新設定檔，注釋為：java     fr.close();     fw.close();   } }結果：載入後的集合：{java03=003, java02=002, java01=001}

          4.計算程式運行次數

 

 importjava.io.File;import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStream;import java.io.PrintStream;import java.util.Properties; public class PropertiesDemo {       publicstatic void main(String[] args) throws IOException {           /*            * 計算程式的運行次數 思路： 1.建立一個設定檔，然後然后里面定義了一個計數器            * 2.每次啟動並執行時候，都取出來，然後自增，然後再存回去            */            Filefile = new File("F:\\pro.ini");           if(!file.exists())                 file.createNewFile();            Propertiespro = new Properties();           pro.load(newFileInputStream(file));// 載入流           Stringvalue = pro.getProperty("count");           intcount = 0;           if(value != null)                 count= Integer.parseInt(value);           count++;//自增           pro.setProperty("count",count + "");// 改變值           pro.store(newFileOutputStream(file), "java for count");// 更新檔案           System.out.println(pro);      } }結果：運行一次，count就+1.

2. 列印流

    

 

import java.io.BufferedReader;import java.io.File;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter; public class PrintStreamDemo {   public static void main(String[] agrs) throws IOException {     // File f=newFile("F:\\demo.txt");     BufferedReader br = new BufferedReader(new InputStreamReader(System.in));     PrintWriter pw = new PrintWriter(System.out,true);//true表示自動重新整理，但是必須是println方法     String line = null;     while ((line = br.readLine()) != null) {        if ("over".equals(line))          return;        pw.println("內容是：" + line);        //pw.flush();      }     br.close();     pw.close();   }}

3. 合并流

   

SequenceInputStreamEnumerationInputStream

 

import java.io.FileOutputStream;import java.io.IOException;import java.io.SequenceInputStream;import java.util.Enumeration;import java.util.Vector;import java.io.FileInputStream; public class SqueDemo {  public static void main(String[] agrs) throws IOException {    Vector<FileInputStream> v = new Vector<FileInputStream>();    v.add(new FileInputStream("F:\\1.txt"));    v.add(new FileInputStream("F:\\2.txt"));    v.add(new FileInputStream("F:\\3.txt"));    Enumeration<FileInputStream> en = v.elements();    SequenceInputStreamsis = new SequenceInputStream(en);     FileOutputStream out = new FileOutputStream("F:\\4.txt");    byte[] b = new byte[1024];    int len = 0;    while ((len = sis.read(b)) != -1) {      out.write(b, 0, len);      out.flush();    }    sis.close();    out.close();   }}

 

4. 切割流

import java.io.FileInputStream;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.IOException;import java.io.SequenceInputStream;import java.util.Enumeration;import java.util.Vector; public class PhotoDemo {  public static void main(String[] args) throws IOException {     FenGe();     HeBing();   }   private static void HeBing() throws FileNotFoundException, IOException {    /* 其實這個也可以使用迴圈，然後添加到集合， */    Vector<FileInputStream> v = new Vector<FileInputStream>();    v.add(new FileInputStream("F:\\part\\1.part"));    v.add(new FileInputStream("F:\\part\\2.part"));    v.add(new FileInputStream("F:\\part\\3.part"));    v.add(new FileInputStream("F:\\part\\4.part"));    v.add(new FileInputStream("F:\\part\\5.part"));    Enumeration<FileInputStream> en = v.elements();    SequenceInputStream sis = new SequenceInputStream(en);     FileOutputStream out = new FileOutputStream("F:\\part\\1.bmp");    byte[] b = new byte[1024];    int len = 0;    while ((len = sis.read(b)) != -1) {      out.write(b, 0, len);      out.flush();    }    sis.close();    out.close();  }   /* 分割 */  private static void FenGe() throws FileNotFoundException, IOException {    FileInputStream input = new FileInputStream("F:\\1.png");     FileOutputStream out = null;    byte[] buf = new byte[1024 * 100];    int count = 1;    int len = 0;    while ((len = input.read(buf)) != -1) {      out = new FileOutputStream("F:\\part\\" + (count++) + ".part");// 分割後的尾碼名自己可以自訂      out.write(buf, 0, len);      out.flush();      out.close();     }    input.close();  } }