客户端与服务端常见的数据交换格式有xml ,json,html
移动端常用http+json
webservice采用html+xml
json
使用fastjson解析json
public static final Object parse(String text); // 把JSON文本parse为JSONObject或者JSONArray
public static final JSONObject parseObject(String text)； // 把JSON文本parse成JSONObject
public static final T parseObject(String text, Class clazz); // 把JSON文本parse为JavaBean
public static final JSONArray parseArray(String text); // 把JSON文本parse成JSONArray
public static final List parseArray(String text, Class clazz); //把JSON文本parse成JavaBean集合
public static final String toJSONString(Object object); // 将JavaBean序列化为JSON文本
public static final String toJSONString(Object object, boolean prettyFormat); // 将JavaBean序列化为带格式的JSON文本
public static final Object toJSON(Object javaObject); 将JavaBean转换为JSONObject或者JSONArray。
xml格式
解析xml一般三种:dom4j sax
dom4j解析xml
package com.xml;
import com.sun.xml.internal.ws.util.StringUtils;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.OutputStreamWriter;
import java.util.List;
/**
* xml解析方式, Dom4j、Sax、Pull
* dom4j不适合大文件的解析，因为它是一下子将文件加载到内存中，所以有可能出现内存溢出，
* sax是基于事件来对xml进行解析的，所以他可以解析大文件的xml，
*/
public class App {
/**
* 创建节点
*/
public static void add(String fileName) {
Document document = DocumentHelper.createDocument();
//根节点
Element beans = document.addElement("beans");
beans.addComment("zhu shi");
//命名空间
beans.addNamespace("context", "http://www.springframework.org/schema/context");
beans.addNamespace("bean", "http://www.springframework.org/schema/bean");
beans.addNamespace("jdbc", "http://www.springframework.org/schema/jsbc");
beans.addNamespace("xsi", "http://www.w3.org/2001/XMLSchema-instance");
beans.addAttribute("xsi:schemaLocation", "http://www.springframework.org/schema/beans \n " +
" http://www.springframework.org/schema/beans/spring-beans.xsd \n " +
" http://www.springframework.org/schema/context \n " +
" http://www.springframework.org/schema/context/spring-context.xsd\n " +
" http://www.springframework.org/schema/aop \n " +
" http://www.springframework.org/schema/aop/spring-aop.xsd");
//节点 list = beans.elements();
for (Element e : list) {
if ("bean".equals(e.getName())) {
String beanName = e.attributeValue("id");
String beanPackage = e.attributeValue("class");
List element = e.elements();
if (!element.equals(null)) {
for (Element ele : element) {
String name = ele.attributeValue("name");
String value = ele.attributeValue("value");
String text = ele.getText();
System.out.println(name+value+text);
}
}
System.out.println(beanPackage + "." + beanName);
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
App.add("d:/file-mianshi/b.xml");
App.xml("d:/file-mianshi/b.xml");
}
}
xml1.png
xml2.png
Java反射
动态获取这个类的所有信息。包括java对象的属性,方法,构造函数等
反射获取类
Class.forName("com.demo.pojo.User");
User.class;
(new User()).getClass();
实例化类(构造对象)
无参构造
Class clazz = Class.forName("...")
Object user = clazz.newInstance();
有参构造
Class clazz = Class.forName("...")
Constructorconstructor = forName.getConstructor(String.class, String.class);
User user = (User) constructor.newInstance("name", "xiaoming");
反射创建api
getDeclaredMethods []
getReturnType()
getParameterTypes()
getDeclaredFields()
setAccessible //允许访问私有成员
springioc的简单实现
读取xml文件
装配bean
反射赋值
新建xml文档
解析xml
package com.xml;
import com.xml.service.Play;
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.SAXReader;
import java.beans.ConstructorProperties;
import java.io.File;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* @author cailonghao
*/
public class Cxml {
/**
* 拿到装载bean的实例
*/
public static Map xml(String file) {
//存放bean
Map> map1 = new HashMap<>();
//存放节点
Map map2 = new HashMap<>();
//存放对象
Map map3 = new HashMap<>();
SAXReader reader = new SAXReader();
try {
//获取根节点并遍历子节点
Document document = reader.read(new File(file));
Element beans = document.getRootElement();
List list = beans.elements();
for (Element element : list) {
String beanName = element.attributeValue("id");
String beanPackage = element.attributeValue("class");
Class clazz = Class.forName(beanPackage);
map1.put(beanName, clazz);
map2.put(beanName, element.elements());
}
//拿到没引用的bean
for (Map.Entry entry : map2.entrySet()) {
String beanName = entry.getKey();
List elements = (List) entry.getValue();
for (Element element : elements) {
if ("property".equals(element.getName())) {
String name = element.attributeValue("name");
Object value = element.attributeValue("ref");
if (value == null) {
value = element.attributeValue("value");
Object object = map1.get(beanName).newInstance();
Field field = object.getClass().getDeclaredField(name);
field.setAccessible(true);
field.set(object, value);
map3.put(beanName, object);
}
}
}
}
;
//拿有构造的
for (Map.Entry entry : map2.entrySet()) {
String beanName = entry.getKey();
List elements = (List) entry.getValue();
List
xml3.png