java 读取本地文件实例详解

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();    }  }}

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();    }  }}