题目:
完成如下功能:
1)有一个(任意)对象,里面有N个properties以及getter和setter方法
2)有一个properties文件,有N个key,value来描述对象中property的值
3)有一个scheme固定的xml,用来描述这个对象
要求写一个解析器:
1)将xml中的占位符,替换为properties文件中的value
2) 将xml解析成对象,调用getter方法的时候可以获得值
3)用面向对象的思想,使该解析器有扩展性
例子见附件,注意:
1)对象是任意对象,不是例子中的Student,对象中的property都是java中的原生类型
2)xml和properties在使用的时候都是根据对象配置好的
3) xml的scheme是固定的,就是附件中的scheme
Student.java文件
- import java.util.Date;
- /**
- * Created by IntelliJ IDEA.
- * User: liuzz
- * Date: 13-11-2
- * Time: 下午11:53
- */
- public class Student {
- private String name;
- private int age;
- private Date birth;
- public String getName() {
- return name;
- }
- public void setName(String name) {
- this.name = name;
- }
- public int getAge() {
- return age;
- }
- public void setAge(int age) {
- this.age = age;
- }
- public Date getBirth() {
- return birth;
- }
- public void setBirth(Date birth) {
- this.birth = birth;
- }
- public String toString(){
- return "[ name = " + name +",age = "+age+",birth = " + birth+"]";
- }
- }
object.properties2文件
- name=a
- age=10
- birth=2003-11-04
- <object class="MyTest.MyTest.Week2.Student">
- <property name="name">
- <value>${name}</value>
- </property>
- <property name="age">
- <value>${age}</value>
- </property>
- <property name="birth">
- <value>${birth}</value>
- </property>
- </object>
- import java.io.BufferedReader;
- import java.io.File;
- import java.io.FileInputStream;
- import java.io.FileNotFoundException;
- import java.io.IOException;
- import java.io.InputStream;
- import java.lang.reflect.AnnotatedType;
- import java.lang.reflect.Field;
- import java.sql.Date;
- import java.text.ParseException;
- import java.text.SimpleDateFormat;
- import java.util.Iterator;
- import java.util.List;
- import java.util.Properties;
- import java.util.Scanner;
- import javax.xml.parsers.DocumentBuilder;
- import javax.xml.parsers.DocumentBuilderFactory;
- import javax.xml.parsers.ParserConfigurationException;
- import org.jdom.Document;
- import org.jdom.Element;
- import org.jdom.JDOMException;
- import org.jdom.input.SAXBuilder;
- import org.w3c.dom.Node;
- import org.w3c.dom.NodeList;
- import org.xml.sax.SAXException;
- import com.google.common.io.Files;
- public class RecoverObject<O> {
- private String propertiesFile;
- private String objectXmlFile;
- private String recoverObjextXmlFile;
- private String clazzName;
- private Properties properties;
- public RecoverObject(String propertiesFile,String objectXmlFile){
- this.propertiesFile = propertiesFile;
- this.objectXmlFile = objectXmlFile;
- this.recoverObjextXmlFile = this.objectXmlFile+".recover";
- this.properties = new Properties();
- initObject();
- }
- private void processXmlFile(String context){
- int pre = -1,s = -1,e = -1;
- StringBuffer buffer = new StringBuffer();
- while((s = context.indexOf("${",pre+1))!=-1){
- e = context.indexOf("}",s + 2);
- buffer.append(context.substring(pre+1,s));
- String attr = context.substring(s+2,e);
- buffer.append(this.properties.get(attr));
- pre = e;
- }
- buffer.append(context.substring(pre+1));
- try {
- Files.write(buffer.toString().getBytes(),new File(this.recoverObjextXmlFile));
- } catch (IOException e1) {
- // TODO Auto-generated catch block
- e1.printStackTrace();
- }
- }
- private void initObject(){
- FileInputStream in;
- try {
- in = new FileInputStream(new File(this.propertiesFile));
- this.properties.load(in);
- in.close();
- } catch (FileNotFoundException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- }
- StringBuffer buffer = new StringBuffer();
- try {
- Scanner scan = new Scanner(new FileInputStream(new File(this.objectXmlFile)));
- while(scan.hasNextLine()){
- buffer.append(scan.nextLine());
- buffer.append("\n");
- }
- } catch (FileNotFoundException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- String context = buffer.toString();
- this.processXmlFile(context);
- }
- public O get(){
- SAXBuilder builder=new SAXBuilder(false);
- Class<?> demo=null;
- try {
- Document doc=builder.build(this.recoverObjextXmlFile);
- Element object=doc.getRootElement();
- this.clazzName = object.getAttributeValue("class");
- demo=Class.forName(this.clazzName);
- O o = (O) demo.newInstance();
- List propertiesList = object.getChildren("property");
- for(Iterator iter = propertiesList.iterator(); iter.hasNext();){
- Element attr = (Element) iter.next();
- String attrName = attr.getAttributeValue("name");
- String attrValue = attr.getChildText("value");
- Field f= demo.getDeclaredField(attrName);
- f.setAccessible(true);
- Class<?> type = f.getType();
- if(type.equals(String.class)){
- f.set(o,attrValue);
- }else if(type.equals(int.class)){
- f.set(o,Integer.parseInt(attrValue));
- }else if(type.equals(java.util.Date.class)){
- SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
- f.set(o,format.parse(attrValue));
- }
- }
- return o;
- } catch (JDOMException e) {
- e.printStackTrace();
- } catch (IOException e) {
- e.printStackTrace();
- } catch (ClassNotFoundException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } catch (InstantiationException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } catch (IllegalAccessException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } catch (NoSuchFieldException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } catch (SecurityException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } catch (IllegalArgumentException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- } catch (ParseException e) {
- // TODO Auto-generated catch block
- e.printStackTrace();
- }
- return null;
- }
- public static void main(String [] args){
- RecoverObject<Student> object = new RecoverObject<Student>("./source/object.properties2","./source/object.xml");
- Student s = object.get();
- System.out.println(s);
- }
- }