Java读取资源文件

Java中读写资源文件最重要的类是Properties,功能大致如下：
1. 读写Properties文件
2. 读写XML文件
3. 不仅可以读写上述两类文件，还可以读写其它格式文件如txt等，只要符合key=value格式即可.

注意：资源文件中含有中文时的处理方法
1. 将中文字符通过工作转成utf8编码，可以通过Java自带的nativetoascii或Eclipse中的属性编辑器。
2. 直接调用 new String(youChineseString.getBytes("ISO-8859-1"), "GBK");

附：WEB程序中加载资源文件的方法
Properties prop = null;
1. prop = Thread.currentThread().getContextClassLoader().getResourceAsStream("filename");
2. prop = this.getClass().getClassLoader().getResourceAsStream("filename");

Properties能读取以key,value存储的任何格式文件。
类结构，



原来它继承了Hashtable并实现了Map接口,这样大家放心了吧。

[java] view
plaincopyprint?

package apistudy;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.UnsupportedEncodingException;

import java.util.Properties;

public class PropertiesTest

{

public static void main(String[] args)

{

String readfile = "d:" + File.separator + "readfile.properties";

String writefile = "d:" + File.separator + "writefile.properties";

String readxmlfile = "d:" + File.separator + "readxmlfile.xml";

String writexmlfile = "d:" + File.separator + "writexmlfile.xml";

String readtxtfile = "d:" + File.separator + "readtxtfile.txt";

String writetxtfile = "d:" + File.separator + "writetxtfile.txt";

readPropertiesFile(readfile); //读取properties文件

writePropertiesFile(writefile); //写properties文件

readPropertiesFileFromXML(readxmlfile); //读取XML文件

writePropertiesFileToXML(writexmlfile); //写XML文件

readPropertiesFile(readtxtfile); //读取txt文件

writePropertiesFile(writetxtfile); //写txt文件

}

//读取资源文件,并处理中文乱码

public static void readPropertiesFile(String filename)

{

Properties properties = new Properties();

try

{

InputStream inputStream = new FileInputStream(filename);

properties.load(inputStream);

inputStream.close(); //关闭流

}

catch (IOException e)

{

e.printStackTrace();

}

String username = properties.getProperty("username");

String passsword = properties.getProperty("password");

String chinese = properties.getProperty("chinese");

try

{

chinese = new String(chinese.getBytes("ISO-8859-1"), "GBK"); // 处理中文乱码

}

catch (UnsupportedEncodingException e)

{

e.printStackTrace();

}

System.out.println(username);

System.out.println(passsword);

System.out.println(chinese);

}

//读取XML文件,并处理中文乱码

public static void readPropertiesFileFromXML(String filename)

{

Properties properties = new Properties();

try

{

InputStream inputStream = new FileInputStream(filename);

properties.loadFromXML(inputStream);

inputStream.close();

}

catch (IOException e)

{

e.printStackTrace();

}

String username = properties.getProperty("username");

String passsword = properties.getProperty("password");

String chinese = properties.getProperty("chinese"); //XML中的中文不用处理乱码，正常显示

System.out.println(username);

System.out.println(passsword);

System.out.println(chinese);

}

//写资源文件，含中文

public static void writePropertiesFile(String filename)

{

Properties properties = new Properties();

try

{

OutputStream outputStream = new FileOutputStream(filename);

properties.setProperty("username", "myname");

properties.setProperty("password", "mypassword");

properties.setProperty("chinese", "中文");

properties.store(outputStream, "author: shixing_11@sina.com");

outputStream.close();

}

catch (IOException e)

{

e.printStackTrace();

}

}

//写资源文件到XML文件，含中文

public static void writePropertiesFileToXML(String filename)

{

Properties properties = new Properties();

try

{

OutputStream outputStream = new FileOutputStream(filename);

properties.setProperty("username", "myname");

properties.setProperty("password", "mypassword");

properties.setProperty("chinese", "中文");

properties.storeToXML(outputStream, "author: shixing_11@sina.com");

outputStream.close();

}

catch (IOException e)

{

e.printStackTrace();

}

}

}

运行本程序所需的资源文件，我是放在D盘根目录，如D:/readfile.properties
1. readfile.properties

username=myname
password=mypassword
chinese=中文

2. writefile.properties

#author: shixing_11@sina.com
#Fri May 28 22:19:44 CST 2010
password=mypassword
chinese=/u4E2D/u6587
username=myname

3. readxmlfile.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>

<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
<entry key="password">mypassword</entry>
<entry key="chinese">中文</entry>
<entry key="username">myname</entry>
</properties>

4. writexmlfile.xml

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
<properties>
<comment>author: shixing_11@sina.com</comment>
<entry key="password">mypassword</entry>
<entry key="chinese">中文</entry>
<entry key="username">myname</entry>
</properties>

5. readtxtfile.txt
username=myname
password=mypassword
chinese=中文
6. writetxtfile.txt

#author: shixing_11@sina.com

#Fri May 28 22:25:16 CST 2010

password=mypassword

chinese=/u4E2D/u6587

username=myname