关于数据流的问题

[cxh7708]

import java.io.*;
public class aa {
public static void main(String [] rags)
{
File f1=new File("F:"+File.separator+"hh.txt");
if(!f1.exists()){
try{
f1.createNewFile();
}
catch(IOException e){
System.out.println(e);
}
}
try {
FileOutputStream rr;
rr=new FileOutputStream(f1);
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
String s="在那遥远的地方，有位好姑娘";
byte[]a=s.getBytes();
rr.Write(a);
rr.close();

}
}
帮忙看一下哪错了，显示rr有错，

[jimyx123]

作用域的问题,rr只作用在try里面

[ychzxx]

File f1 = new File("e:" + File.separator + "hh.txt");
if (!f1.exists()) {
try {
f1.createNewFile();
} catch (IOException e) {
System.out.println(e);
}
}
FileOutputStream rr;
try {
rr = new FileOutputStream(f1);
String s = "在那遥远的地方，有位好姑娘";
byte[] a = s.getBytes();
rr.write(a);
rr.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO 自动生成 catch 块
e.printStackTrace();
}

[walkman_22]

rr 应该拿出try语句块。

[智鹿软件]

字节流：

package IO;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
/**
 * test.getBytes("iso8859-1"))
 * 用OutputStream和InputStream实现文件的写入和读取(字节的写入和读取)
 *
 */
public class InAndOut {
	String path="e:\\abc.txt";
	public static void main(String[] args) {
		InAndOut io=new InAndOut ();
		io.write("我是邪恶少年!");
		io.read();
	}
	public void write(String content)
	{
		File f=new File (path);
		boolean add=true;//是否写入
		try {
			if (f.exists()==false) {
				f.createNewFile();
				FileOutputStream os=new FileOutputStream (f);//不用判断是否写入
				//FileOutputStream os=new FileOutputStream (f,add);//要判断是否写入
				os.write(content.getBytes());
				os.flush();
				os.close();
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	public void read()
	{
		try {
			InputStream is=new FileInputStream(path);
			//BufferedInputStream bis=new BufferedInputStream(new FileInputStream(path));
			int temp=0;
			String test="";
			try {
				while ((temp=is.read())!=-1) {
					test+=(char)temp;
				}
				System.out.println(new String (test.getBytes("iso8859-1")));//会出现乱码
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}

字符流：

package IO;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Reader;
/**
 * 
 *用read和write实现文件的写入和读取(字符的写入和读取)
 *
 */
public class ReadAndWrite {
	//定义文件的路径，一边写入和读取使用
	String path="e:\\abc.txt";
	
	public static void main(String[] args) {
		ReadAndWrite r=new ReadAndWrite ();
		r.writeFile("我乃邪恶少年是也！");
		r.readFile();
	}
	private void readFile() {
		// TODO Auto-generated method stub
		try {
			Reader r=new BufferedReader (new FileReader(path));
			String test="";
			int temp=0;
			try {
				while ((temp=r.read())!=-1) {
					test+=(char)temp;
				}
				System.out.println(test);
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
	private void writeFile(String content) {
		// TODO Auto-generated method stub
		File f=new File (path);
		if (f.exists()==false) {
			try {
				f.createNewFile();
				FileWriter fw=new FileWriter (f);
				fw.write(content);
				fw.flush();
				fw.close();
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			
		}else {
			System.out.println(path+"已存在,写入失败,源文件是");
		}
	}
}