Go语言视频零基础入门到精通

五菱

[1] String fileReaderStringHandle(String fileName)
将文件（由fileName指定）读入到一个字符串；
[2] byte[] fileReaderByteHandle(String fileName)
将文件（由fileName指定）读入到一个字节数组；
[3] void fileWriterHandle(String fileName, String text)
将字符串（由text指定）写出到一个文件（由fileName指定）。
IOUtil.java

import java.io.BufferedInputStream;

import java.io.BufferedReader;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileReader;

import java.io.IOException;

import java.io.PrintWriter;

public class IOUtil {

/**

* 将文件读入到一个String，利用FileReader+BufferedReader(提供readLine方法)

*

* @param fileName

* @return String

*/

public static String fileReaderStringHandle(String fileName) {

StringBuilder sb = new StringBuilder();

try {

BufferedReader in = new BufferedReader(new FileReader(new File(

fileName).getAbsoluteFile()));

try {

String s;

while ((s = in.readLine()) != null) {

sb.append(s);

sb.append(" ");

}

} finally {

in.close();

}

} catch (IOException e) {

throw new RuntimeException(e);

}

return sb.toString();

}

/**

* 使用FileInputStream+BufferedInputStream以byte的方式处理文件

*

* @param fileName

* @return byte[]

*/

public static byte[] fileReaderByteHandle(String fileName) {

byte[] data = null;

try {

BufferedInputStream bf = new BufferedInputStream(

new FileInputStream(fileName));

try {

data = new byte[bf.available()];

bf.read(data);

} finally {

bf.close();

}

} catch (IOException e) {

throw new RuntimeException(e);

}

return data == null ? new byte[] {} : data;

}

/**

* 将指定的text写入到文件名为fileName的文件中

*

* @param fileName

* @param text

*/

public static void fileWriterHandle(String fileName, String text) {

try {

PrintWriter out = new PrintWriter(new File(fileName)

.getAbsoluteFile());

try {

out.print(text);

} finally {

out.close();

}

} catch (IOException e) {

throw new RuntimeException(e);

}

}

public static void main(String[] args) throws IOException {

System.out.print(fileReaderStringHandle("src/IOUtil.java"));

for (byte b : fileReaderByteHandle("src/IOUtil.java"))

System.out.print(b);

fileWriterHandle("zj.txt",

fileReaderStringHandle("src/IOUtil.java"));

}

}