读取Properties文件的六种方法

1。使用java.util.Properties类的load()方法

示例： InputStream in = new BufferedInputStream(new FileInputStream(name));
Properties p = new Properties();
p.load(in);

2。使用java.util.ResourceBundle类的getBundle()方法
示例： ResourceBundle rb = ResourceBundle.getBundle(name, Locale.getDefault());

3。使用java.util.PropertyResourceBundle类的构造函数
示例： InputStream in = new BufferedInputStream(new FileInputStream(name));
ResourceBundle rb = new PropertyResourceBundle(in);

4。使用class变量的getResourceAsStream()方法
示例： InputStream in = JProperties.class.getResourceAsStream(name);
Properties p = new Properties();
p.load(in);

5。使用class.getClassLoader()所得到的java.lang.ClassLoader的getResourceAsStream()方法
示例： InputStream in = JProperties.class.getClassLoader().getResourceAsStream(name);
Properties p = new Properties();
p.load(in);

6。使用java.lang.ClassLoader类的getSystemResourceAsStream()静态方法
示例： InputStream in = ClassLoader.getSystemResourceAsStream(name);
Properties p = new Properties();
p.load(in);

补充

Servlet中可以使用javax.servlet.ServletContext的getResourceAsStream()方法
示例：InputStream in = context.getResourceAsStream(path);
Properties p = new Properties();
p.load(in);

完整的示例，可以参考附件文件
 
JProperties.java文件

//import javax.servlet.ServletContext;
import java.util.*;
import java.io.InputStream;
import java.io.IOException;
import java.io.BufferedInputStream;
import java.io.FileInputStream;


public class JProperties {

public final static int BY_PROPERTIES = 1;
public final static int BY_RESOURCEBUNDLE = 2;
public final static int BY_PROPERTYRESOURCEBUNDLE = 3;
public final static int BY_CLASS = 4;
public final static int BY_CLASSLOADER = 5;
public final static int BY_SYSTEM_CLASSLOADER = 6;

public final static Properties loadProperties(final String name, final int type) throws IOException {
Properties p = new Properties();
InputStream in = null;
if (type == BY_PROPERTIES) {
in = new BufferedInputStream(new FileInputStream(name));
assert (in != null);
p.load(in);
} else if (type == BY_RESOURCEBUNDLE) {
ResourceBundle rb = ResourceBundle.getBundle(name, Locale.getDefault());
assert (rb != null);
p = new ResourceBundleAdapter(rb);
} else if (type == BY_PROPERTYRESOURCEBUNDLE) {
in = new BufferedInputStream(new FileInputStream(name));
assert (in != null);
ResourceBundle rb = new PropertyResourceBundle(in);
p = new ResourceBundleAdapter(rb);
} else if (type == BY_CLASS) {
assert (JProperties.class.equals(new JProperties().getClass()));
in = JProperties.class.getResourceAsStream(name);
assert (in != null);
p.load(in);
// return new JProperties().getClass().getResourceAsStream(name);
} else if (type == BY_CLASSLOADER) {
assert (JProperties.class.getClassLoader().equals(new JProperties().getClass().getClassLoader()));
in = JProperties.class.getClassLoader().getResourceAsStream(name);
assert (in != null);
p.load(in);
// return new JProperties().getClass().getClassLoader().getResourceAsStream(name);
} else if (type == BY_SYSTEM_CLASSLOADER) {
in = ClassLoader.getSystemResourceAsStream(name);
assert (in != null);
p.load(in);
}

if (in != null) {
in.close();
}
return p;

}

// ---------------------------------------------- servlet used


// ---------------------------------------------- support class


public static class ResourceBundleAdapter extends Properties {
public ResourceBundleAdapter(ResourceBundle rb) {
assert (rb instanceof java.util.PropertyResourceBundle);
this.rb = rb;
java.util.Enumeration e = rb.getKeys();
while (e.hasMoreElements()) {
Object o = e.nextElement();
this.put(o, rb.getObject((String) o));
}
}

private ResourceBundle rb = null;

public ResourceBundle getBundle(String baseName) {
return ResourceBundle.getBundle(baseName);
}

public ResourceBundle getBundle(String baseName, Locale locale) {
return ResourceBundle.getBundle(baseName, locale);
}

public ResourceBundle getBundle(String baseName, Locale locale, ClassLoader loader) {
return ResourceBundle.getBundle(baseName, locale, loader);
}

public Enumeration getKeys() {
return rb.getKeys();
}

public Locale getLocale() {
return rb.getLocale();
}

public Object getObject(String key) {
return rb.getObject(key);
}

public String getString(String key) {
return rb.getString(key);
}

public String[] getStringArray(String key) {
return rb.getStringArray(key);
}

protected Object handleGetObject(String key) {
return ((PropertyResourceBundle) rb).handleGetObject(key);
}

}

}

JPropertiesTest.java文件


package com.kindani.test;

import junit.framework.*;
import com.kindani.JProperties;

//import javax.servlet.ServletContext;
import java.util.Properties;

public class JPropertiesTest extends TestCase {
JProperties jProperties;
String key = "helloworld.title";
String value = "Hello World!";

public void testLoadProperties() throws Exception {
String name = null;
Properties p = new Properties();

name = "C:\IDEAP\Properties4Methods\src\com\kindani\test\LocalStrings.properties";
p = JProperties.loadProperties(name, JProperties.BY_PROPERTIES);
assertEquals(value, p.getProperty(key));

name = "com.kindani.test.LocalStrings";
p = JProperties.loadProperties(name,JProperties.BY_RESOURCEBUNDLE);
assertEquals(value, p.getProperty(key));
assertEquals(value,((JProperties.ResourceBundleAdapter)p).getString(key));

name = "C:\IDEAP\Properties4Methods\src\com\kindani\test\LocalStrings.properties";
p = JProperties.loadProperties(name, JProperties.BY_PROPERTYRESOURCEBUNDLE);
assertEquals(value, p.getProperty(key));
assertEquals(value,((JProperties.ResourceBundleAdapter)p).getString(key));

name = "\com\kindani\test\LocalStrings.properties";
p = JProperties.loadProperties(name, JProperties.BY_SYSTEM_CLASSLOADER);
assertEquals(value, p.getProperty(key));

name = "\com\kindani\test\LocalStrings.properties";
p = JProperties.loadProperties(name, JProperties.BY_CLASSLOADER);
assertEquals(value, p.getProperty(key));

name = "test\LocalStrings.properties";
p = JProperties.loadProperties(name, JProperties.BY_CLASS);
assertEquals(value, p.getProperty(key));
}


}

properties文件与JPropertiesTest.java文件相同的目录下
LocalStrings.properties文件
# $Id: LocalStrings.properties,v 1.1 2000/08/17 00:57:52 horwat Exp $

# Default localized resources for example servlets
# This locale is en_US

helloworld.title=Hello World!

requestinfo.title=Request Information Example
requestinfo.label.method=Method:
requestinfo.label.requesturi=Request URI:
requestinfo.label.protocol=Protocol:
requestinfo.label.pathinfo=Path Info:
requestinfo.label.remoteaddr=Remote Address:

requestheader.title=Request Header Example

requestparams.title=Request Parameters Example
requestparams.params-in-req=Parameters in this request:
requestparams.no-params=No Parameters, Please enter some
requestparams.firstname=First Name:
requestparams.lastname=Last Name:

cookies.title=Cookies Example
cookies.cookies=Your browser is sending the following cookies:
cookies.no-cookies=Your browser isn't sending any cookies
cookies.make-cookie=Create a cookie to send to your browser
cookies.name=Name:
cookies.value=Value:
cookies.set=You just sent the following cookie to your browser:

sessions.title=Sessions Example
sessions.id=Session ID:
sessions.created=Created:
sessions.lastaccessed=Last Accessed:
sessions.data=The following data is in your session:
sessions.adddata=Add data to your session
sessions.dataname=Name of Session Attribute:
sessions.datavalue=Value of Session Attribute:

-----------------------------------------------------------------------------------------------------------------------------------------------

Java对properties配置文件的操作


package com.yorsun;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServlet;


public class PropertiesUnit {
private String filename;

private Properties p;

private FileInputStream in;

private FileOutputStream out;

public PropertiesUnit(String filename) {
this.filename = filename;
File file = new File(filename);
try {
in = new FileInputStream(file);
p = new Properties();
p.load(in);
in.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
System.err.println("配置文件config.properties找不到！");
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
System.err.println("读取配置文件config.properties错误！");
e.printStackTrace();
}
}

public static String getConfigFile(HttpServlet hs) {
return getConfigFile(hs, "config.properties");
}


private static String getConfigFile(HttpServlet hs, String configFileName) {
String configFile = "";
ServletContext sc = hs.getServletContext();
configFile = sc.getRealPath("/" + configFileName);
if (configFile == null || configFile.equals("")) {
configFile = "/" + configFileName;
}
// TODO Auto-generated method stub
return configFile;
}

public void list() {
p.list(System.out);
}

public String getValue(String itemName) {
return p.getProperty(itemName);
}

public String getValue(String itemName, String defaultValue) {
return p.getProperty(itemName, defaultValue);
}

public void setValue(String itemName, String value) {
p.setProperty(itemName, value);
}

public void saveFile(String filename, String description) throws Exception {
try {
File f = new File(filename);
out = new FileOutputStream(f);
p.store(out, description);
out.close();
} catch (IOException ex) {
throw new Exception("无法保存指定的配置文件:" + filename);
}
}

public void saveFile(String filename) throws Exception{
saveFile(filename,"");
}

public void saveFile() throws Exception{
if(filename.length()==0)
throw new Exception("需指定保存的配置文件名");
saveFile(filename);
}

public void deleteValue(String value){
p.remove(value);
}

public static void main(String args[]){
String file="/eclipse/workspace/NewsTest/WEB-INF/config.properties";
// String file="D:\eclipse\workspace\NewsTest\WEB-INF\config.properties";
PropertiesUnit pu=new PropertiesUnit(file);
pu.list();
}

}

---------------------------------------------------------------------------------------------------------------------------------

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

public class ReadPropertiesFile ...{

public void readPropertiesFile(String fileName) throws FileNotFoundException ...{
String str = "";
Properties prop = new Properties();

InputStream stream = null;

//读取这个类在同一包中的properties文件
//stream = getClass().getClassLoader().getResourceAsStream(fileName);
System.out.println("path:" + getClass().getResource(fileName));


//读取SRC下的的properties文件
String path = getClass().getResource("/").getPath();
stream = new BufferedInputStream(new FileInputStream(new File(path+fileName)));

try ...{
prop.load(stream);
str = prop.getProperty("localname");
System.out.println("localname:" + str);
System.out.println("properties:" + prop);
stream.close();

} catch (IOException e) ...{
// TODO Auto-generated catch block
e.printStackTrace();
}
}


public static void main(String[] args) throws FileNotFoundException ...{
// TODO Auto-generated method stub
new ReadPropertiesFile().readPropertiesFile("config.properties");

}

}

--------------------------------------------------------------------------------------------------------------------------------------

//=================sprin配置文件================================
<bean
id="userService"
class="com.thtf.ezone.ezesb.jmx.admin.service.impl.UserServiceImpl">
<property
name="filePath"
value="config/userInfo.properties" />
</bean>

//=================java文件================================

package com.thtf.ezone.ezesb.jmx.admin.service.impl;

import java.io.FileInputStream;
import java.io.IOException;
import java.util.Properties;

public class UserServiceImpl implements UserService {

String filePath = null;

public void setFilePath(String filePath) {
this.filePath = filePath;
}

public static void main(String dd[])throws Exception{

Properties p = new Properties();
FileInputStream ferr=new FileInputStream((getClass().getClassLoader()
.getResource("") + filePath).toString().substring(6));// 用subString(6)去掉：file:/try{
p.load(ferr);
ferr.close();
Set s = p.keySet();
Iterator it = s.iterator();
while(it.hasNext()){
String id = (String)it.next();
String value = p.getProperty(id);
System.out.println(id+":="+value);
}
}catch(Exception e){
e.printStackTrace();
}
}
}

//==============databaseconfing.properties 文件=====================

#----------------------------------
# sql server 2000数据厍连接信息
#----------------------------------
dp.sd.DataBaseTyp=mssql
DataBaseHost=127.0.0.1:1433
DataBase=formpro
UserName=sa
PassWord=01
#----------------------------------
# mysql 数据厍连接信息
#----------------------------------
#DataBaseHost=127.0.0.1:3306
#DataBaseTyp=mysql
#DataBase=snow
#UserName=root
#PassWord=01
//==========================运行结果=======================

PassWord:=01
DataBaseHost:=127.0.0.1:1433
DataBase:=formpro
dp.sd.DataBaseTyp:=mssql
UserName:=sa