java I/O流，输入流，输出流，输入输出流，InputStream，FileInputStream，文件流，byte，url

//把F:/test/distribute.sql这个文件读入到byte数组中，返回这个数组

package com.cus.systemFunction.disCom;

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import org.apache.log4j.Logger;

/**
 * 说明：把文件读到byte数组
 * @author  xxx

 * 创建时间：2010-8-5  下午01:21:33
 */

public class FileToByteArray {
 static Logger logger = Logger.getLogger(FileToByteArray.class.getName());
 String outDir = "";

//getByteArray() 方法返回一个byte数组
 public  byte[] getByteArray() throws Exception { 

 

//  String path= getClass().getResource("/").getPath();
//  outDir = path.trim().substring(1,path.length()-5)+"outputDir/generator/sqlScript/";
//BufferedInputStream in = new BufferedInputStream(new FileInputStream(outDir+"distribute.sql"));

  BufferedInputStream in = new BufferedInputStream(new FileInputStream("F://test//distribute.sql"));
        ByteArrayOutputStream out = new ByteArrayOutputStream(1024);
       
        System.out.println("Available bytes:" + in.available());        
       
        byte[] temp = new byte[1024];        
        int size = 0;        
        while ((size = in.read(temp)) != -1) {        
            out.write(temp, 0, size);        
        }        
        in.close();        
       
        byte[] content = out.toByteArray();        
        System.out.println("Readed bytes count:" + content.length);        
        return content;
 }
 
}

 

 

//把上面返回的这个byte数组的内容，读入到C盘目录下的distributeCopy.sql文件中

package com.cus.systemFunction.disCom;

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;

public class TestMain {
 public static void main(String args[]) throws Exception{

 FileToByteArray fileToByteArray = new FileToByteArray();
  byte[] buffer = fileToByteArray.getByteArray();
 
   FileOutputStream outf=new FileOutputStream("C://distributeCopy.sql");
   BufferedOutputStream bufferout= new BufferedOutputStream(outf);
   bufferout.write(buffer);
   bufferout.flush();
   bufferout.close();
  
 }
}

 

---

 

 /**
  * 读文件,根据文件名,返回文件内容字符串
  */
 public String readFile(String filePath){
  StringBuffer sb = new StringBuffer();
        try {
            String encoding = "UTF-8";
            File file = new File(filePath);
            //判断文件是否存在
            if(file.isFile() && file.exists()){
                InputStreamReader read = new InputStreamReader(new FileInputStream(file),encoding);//考虑到编码格式
                BufferedReader bufferedReader = new BufferedReader(read);
                String lineTxt = null;
                while((lineTxt = bufferedReader.readLine()) != null){
                //    System.out.println(lineTxt);
                 sb.append(lineTxt).append("\r\n");
                }
                read.close();
            }else{
             System.out.println(sb.append("找不到指定的文件:" + filePath));
            }
        } catch (Exception e) {
            System.out.println(sb.append("读取文件内容出错"));
            e.printStackTrace();
        }
  return sb.toString();
    }

 

 

 ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

//文件拷贝，把一个文件读入InputStream,然后把InputStream写入另一个文件

public class Test2 {

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  File file = new File("D:\\sampleanalysisreport\\28.docx");
  try {
   InputStream inputStream = new FileInputStream(file);
   try {
    saveToFile(inputStream,
      "D:\\sampleanalysisreport_sub\\28_bak3.docx");
   } catch (IOException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }
  } catch (FileNotFoundException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
 }

//把InputStream写入文件

 public static void saveToFile(InputStream inputStream, String fileName)
   throws IOException {
  File file = new File(fileName);
  OutputStream os = null;
  try {
   os = new FileOutputStream(file);
   byte buffer[] = new byte[4 * 1024];
   int len = 0;
   while((len = inputStream.read(buffer)) != -1){
    os.write(buffer,0,len);
   }
   os.flush();
  } catch (Exception e) {
   e.printStackTrace();
  } finally {
   try {
    os.close();
   } catch (Exception e) {
    e.printStackTrace();
   }
  }
 }
}

 

 

-------------------------------------------------------------------------------

 /**
  * 把指定url下载的文件保存下来
  * @param destUrl
  * @param fileName
  * @return
  */
 public static boolean saveToFile(String destUrl, String fileName) {
  boolean result = false;
  FileOutputStream fos = null;
  BufferedInputStream bis = null;
  HttpURLConnection httpUrl = null;
  URL url = null;
  byte[] buf = new byte[1024];
  int size = 0;
  try {
   url = new URL(destUrl);
   httpUrl = (HttpURLConnection) url.openConnection();
   httpUrl.connect();
   bis = new BufferedInputStream(httpUrl.getInputStream());
   fos = new FileOutputStream(fileName);
   while ((size = bis.read(buf)) != -1)
    fos.write(buf, 0, size);
   fos.close();
   bis.close();
   System.out.println("saveToFile---------successful");
   result = true;
  } catch (IOException e) {
   // TODO: handle exception
   System.out.println("saveToFile---------failure");
   e.printStackTrace();
  }finally{
   httpUrl.disconnect();
  }
  return result;
 }

 

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String与InputStream相互转换

1.String to InputStream

String str = "String与InputStream相互转换";

InputStream   in_nocode   =   new   ByteArrayInputStream(str.getBytes());  
InputStream   in_withcode   =   new   ByteArrayInputStream(str.getBytes("UTF-8"));  

 

 

2.InputStream to String

    这里提供几个方法。

方法1：

  public String convertStreamToString(InputStream is) {   

   BufferedReader reader = new BufferedReader(new InputStreamReader(is));   

        StringBuilder sb = new StringBuilder();   

    

        String line = null;   

        try {   

            while ((line = reader.readLine()) != null) {   

                sb.append(line + "/n");   

            }   

        } catch (IOException e) {   

            e.printStackTrace();   

        } finally {   

            try {   

                is.close();   

            } catch (IOException e) {   

                e.printStackTrace();   

            }   

        }   

    

        return sb.toString();   

    }   

 

方法2：

public   String   inputStream2String   (InputStream   in)   throws   IOException   {
        StringBuffer   out   =   new   StringBuffer();
        byte[]   b   =   new   byte[4096];
        for   (int   n;   (n   =   in.read(b))   !=   -1;)   {
                out.append(new   String(b,   0,   n));
        }
        return   out.toString();
} 

方法3：
public   static   String   inputStream2String(InputStream   is)   throws   IOException{
        ByteArrayOutputStream   baos   =   new   ByteArrayOutputStream();
        int   i=-1;
        while((i=is.read())!=-1){
        baos.write(i);
        }
       return   baos.toString();
}

 

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