Java I/O 教程(九) FileWriter和FileReader
FileWriter
Java FileWriter 用于往文件中写入字符数据。
不像FileOutputStream类,你无需转换字符串成字节数组,因为它提供了直接写字符串的方法。
类定义
public class FileWriter extends OutputStreamWriter
构造函数
FileWriter(File file)
Constructs a FileWriter object given a File object.
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FileWriter(File file, boolean append)
Constructs a FileWriter object given a File object.
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FileWriter(FileDescriptor fd)
Constructs a FileWriter object associated with a file descriptor.
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FileWriter(String fileName)
Constructs a FileWriter object given a file name.
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FileWriter(String fileName, boolean append)
Constructs a FileWriter object given a file name with a boolean indicating whether or not to append the data written.
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方法
-
Methods inherited from class java.io.OutputStreamWriter
close, flush, getEncoding, write, write, write
请参考:OutputStreamWriter
例子
package com.dylan.io;
import java.io.FileWriter;
/**
* @author xusucheng
* @create 2018-01-07
**/
public class FileWriterExample {
public static void main(String args[]){
try{
FileWriter fw=new FileWriter("D:\\testout.txt");
fw.write("Welcome to java.io.");
fw.close();
}catch(Exception e){System.out.println(e);}
System.out.println("Success...");
}
}
FileReader
Java FileReader 用于从文件中读取数据。返回字符数据。
类定义
public class FileReader extends InputStreamReader
构造函数
FileReader(File file)
Creates a new
FileReader, given the
File
to read from.
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FileReader(FileDescriptor fd)
Creates a new
FileReader, given the
FileDescriptor
to read from.
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FileReader(String fileName)
Creates a new
FileReader, given the name of the file to read from.
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方法
-
Methods inherited from class java.io.InputStreamReader
close, getEncoding, read, read, ready
具体请参考:InputStreamReader
例子
package com.dylan.io;
import java.io.FileReader;
/**
* @author xusucheng
* @create 2018-01-07
**/
public class FileReaderExample {
public static void main(String args[])throws Exception{
FileReader fr=new FileReader("D:\\testout.txt");
int i;
while((i=fr.read())!=-1)
System.out.print((char)i);
fr.close();
}
}