java 读取本地文件实例详解

用javax.xml、w3c解析

实例代码：

package cn.com.xinli.monitor.utils;

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import java.io.File;

/**

* Created by jiyy on 2017/4/6.

*/

public class ReadXmlTest {

public static void main(String[] args){

Element element = null;

// 可以使用绝对路劲

File f = new File("D:/workspace-idea/monitor-service/src/main/resources/logMonitor.xml");

// documentBuilder为抽象不能直接实例化(将XML文件转换为DOM文件)

DocumentBuilder db = null;

DocumentBuilderFactory dbf = null;

try {

// 返回documentBuilderFactory对象

dbf = DocumentBuilderFactory.newInstance();

// 返回db对象用documentBuilderFatory对象获得返回documentBuildr对象

db = dbf.newDocumentBuilder();

// 得到一个DOM并返回给document对象

Document dt = db.parse(f);

// 得到一个elment根元素

element = dt.getDocumentElement();

// 获得根节点

System.out.println("根元素：" + element.getNodeName());

}catch (Exception e ){

e.printStackTrace();

}

}

}

用dom4j解析

package cn.com.xinli.monitor.test;

import org.apache.commons.io.IOUtils;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.DocumentHelper;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.io.InputStream;

import java.net.URISyntaxException;

/**

* Created by jiyy on 2017/4/6.

*/

public class ReadFileTest {

public static void main(String[] args){

//方法一：本地绝对路径获取xml文件内容，项目外的路径

String fileUrl = "/D:/workspace-idea/monitor-service/src/main/resources/logMonitor.xml";

InputStream fis = null;

try {

fis = new FileInputStream(new File(fileUrl));

String content = IOUtils.toString(fis,"UTF-8");

Document document = DocumentHelper.parseText(content);

} catch (java.io.IOException e) {

e.printStackTrace();

} catch (DocumentException e) {

e.printStackTrace();

}

//方法二:项目绝对路径是在本class文件所在项目的根目录下找，也就是classes/下

try {

String content2 = IOUtils.toString(ReadFileTest.class.getResourceAsStream("/logMonitor.xml"), "UTF-8");

Document document2 = DocumentHelper.parseText(content2);

} catch (IOException e) {

e.printStackTrace();

}catch (DocumentException e) {

e.printStackTrace();

}

//方法三：相对目录，在本ReadFileTest编译后的.class文件同级目录

try {

String content3 = IOUtils.toString(ReadFileTest.class.getResourceAsStream("logMonitor.xml"), "UTF-8");

Document document3 = DocumentHelper.parseText(content3);

} catch (IOException e) {

e.printStackTrace();

}catch (DocumentException e) {

e.printStackTrace();

}

//方法四：相对目录，在本ReadFileTest编译后的.class文件上级目录的config目录下

try {

String content4 = IOUtils.toString(ReadFileTest.class.getResourceAsStream("../config/logMonitor.xml"), "UTF-8");

Document document4 = DocumentHelper.parseText(content4);

} catch (IOException e) {

e.printStackTrace();

}catch (DocumentException e) {

e.printStackTrace();

}

//方法五：动态获取相对目录

try {

String xmlPath = "logMonitor.xml";

//获取当前类加载的根目录，如：/C:/Program Files/Apache/Tomcat 6.0/webapps/fee/WEB-INF/classes/

String path = ReadFileTest.class.getClassLoader().getResource("").toURI().getPath();

// 把文件读入文件输入流，存入内存中

FileInputStream in = new FileInputStream(new File(path + xmlPath));

String content5 = IOUtils.toString(in,"UTF-8");

Document document5 = DocumentHelper.parseText(content5);

} catch (IOException e) {

e.printStackTrace();

} catch (DocumentException e) {

e.printStackTrace();

}catch (URISyntaxException e) {

e.printStackTrace();

}

}

}

感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！