FileInputStream
和FileOutputStream
用于从本机文件系统上的文件读取数据并将数据写入。
以下是使用FileInputStream
从文件读取数据的示例。
文件:FileInputStreamExample.java -
package com.yiibai.tutorial.io;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
/**
* @author yiibai
* FileInputStreamExample.java
* Nov 5, 2016
*/
public class FileInputStreamExample {
public static void main(String[] args) {
File file=new File("file.txt");
try {
FileInputStream fileInputStream=new FileInputStream(file);
int b;
while((b=fileInputStream.read())!=-1){
System.out.print((char)b);
}
fileInputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
执行上面示例代码,得到以下结果:
This is an example of reading data from file.
以下是使用FileOutputStream
将数据写入文件的示例。文件:FileOutputStreamExample.java -
package com.yiibai.tutorial.io;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* @author yiibai
* FileOutputStreamExample.java
* Nov 5, 2016
*/
public class FileOutputStreamExample {
public static void main(String[] args) {
String data="This is an example of writing data to a file.";
File file=new File("outfile.txt");
try {
FileOutputStream fileOutputStream = new FileOutputStream(file);
fileOutputStream.write(data.getBytes());
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
执行上面示例代码,得到以下结果:
This is an example of writing data to a file.
以下程序使用两个文件流将数据从一个文件复制到另一个文件。
文件:FileStreamExample.java -
package com.yiibai.tutorial.io;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
/**
* @author yiibai
* FileStreamExample.java
* Nov 5, 2016
*/
public class FileStreamExample {
public static void main(String[] args) {
File inFile=new File("input.txt");
File outFile=new File("output.txt");
try {
FileInputStream fileInputStream=new FileInputStream(inFile);
FileOutputStream fileOutputStream=new FileOutputStream(outFile);
int i;
while((i=fileInputStream.read())!=-1){
fileOutputStream.write(i);
}
fileInputStream.close();
fileOutputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
输入文件 - input.txt 的内容:
This is an example of the FileInputStream and FileOutputStream.
输出文件 - output.txt 的内容:
This is an example of the FileInputStream and FileOutputStream.