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?昨天接手一个webservice项目，算是二次开发吧，，看了两天webservice和annotation，记录下我的学习笔记
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注解：
???? @XmlAccessor(XmlAccessType.Field)表示 注解（@XmlElement name=""）字段要加在字段上面，如果没有@XmlAccessor注解的话要将@XmlElement注解加在方法上(个人认为：应该是默认是加在getter方法上面)。
????? @XmlRootElement(name="")生成的xml文件的根元素。
?????? javabean类一定要有个无参构造函数，因为要在字段赋值时用到无参构造函数，否则会报异常：
????? does not have a no-arg default constructor
????? 嵌套元素，诸如：
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<student>
??? <class>
??????? <班级编号>software</班级编号>
??? </class>
??? <学号>1001</学号>
??? <姓名>sun</姓名>
</student>
需要构造一静态内部类，因为内部类不需要访问外围类中的数据，所以设置为静态类（构造内部类对象时不需要外围类的对象），代码如下：
//@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "student")
@XmlType(propOrder = { "classId","id","stuName" })
public class Student {
?private int id;
?private String stuName;
?private ClassId classId;
?public static class ClassId {
??private String className;
??public ClassId(String className) {
???this.className = className;
??}
??public ClassId() {
??}
??@XmlElement(name = "班级编号")
??public String getClassName() {
???return className;
??}
??public void setClassName(String className) {
???this.className = className;
??}
?}
?public Student(int id,String stuName) {
??this.id = id;
??this.stuName = stuName;
?}
?public Student() {
?}
?@XmlElement(name = "学号")
?public int getId() {
??return id;
?}
?public void setId(int id) {
??this.id = id;
?}
?@XmlElement(name = "姓名")
?public String getstuName() {
??return stuName;
?}
?public void setstuName(String stuName) {
??this.stuName = stuName;
?}
?@XmlElement(name = "class")
?public ClassId getClassId() {
??return classId;
?}
?public void setClassId(ClassId classId) {
??this.classId = classId;
?}
}
之所以要注释掉@XmlAccessorType,是因为注解是加在getter方法上的，否则会出现
There are two properties named "classId" 异常
因为在生成XML文件时，元素的出现位置是随机的，如果要固定元素的前后位置，就要加入@XmlType(proOrder={})注解。
2、编组List对象，诸如：
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<学校>
??? <school>
??????? <班级>
??????????? <班级编号>software</班级编号>
??????? </班级>
??????? <学号>1001</学号>
??????? <姓名>sun</姓名>
??? </school>
??? <school>
??????? <班级>
??????????? <班级编号>software</班级编号>
??????? </班级>
??????? <学号>1002</学号>
??????? <姓名>klov</姓名>
??? </school>
</学校>
?则需要
//@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "学生")
@XmlType(propOrder = { "classId","stuName" })
public class Student {
?private int id;
?private String stuName;
?private ClassId classId;
?public static class ClassId {
??private String className;
??public ClassId(String className) {
???this.className = className;
??}
??public ClassId() {
??}
??@XmlElement(name = "班级编号")
??public String getClassName() {
???return className;
??}
??public void setClassName(String className) {
???this.className = className;
??}
?}
?public Student(int id,String stuName) {
??this.id = id;
??this.stuName = stuName;
?}
?public Student() {
?}
?@XmlElement(name = "学号")
?public int getId() {
??return id;
?}
?public void setId(int id) {
??this.id = id;
?}
?@XmlElement(name = "姓名")
?public String getstuName() {
??return stuName;
?}
?public void setstuName(String stuName) {
??this.stuName = stuName;
?}
?@XmlElement(name = "班级")
?public ClassId getClassId() {
??return classId;
?}
?public void setClassId(ClassId classId) {
??this.classId = classId;
?}
}
School类
?
@XmlAccessorType(XmlAccessType.FIELD)
@XmlRootElement(name = "学校")
public class School {
//?@XmlElement(name = "student")
?@XmlElements(value = { @XmlElement(type=Student.class)})
?private List<Student> school = new ArrayList<Student>();
?public List<Student> getSchool() {
??return school;
?}
?public void setSchool(List<Student> school) {
??this.school = school;
?}
?
?public synchronized void addStu(Student stu){
??if(school == null){
???school = new ArrayList<Student>();
??}
??school.add(stu);
?}
}
?
测试类
@Test
?public void testGetId() {
??Student stu = new Student(1001,"sun") ;
??Student stu2 = new Student(1002,"klov") ;
??Student.ClassId classId = new Student.ClassId("software");
??stu.setClassId(classId);
??stu2.setClassId(classId);
??
??List<Student> stuList = new ArrayList<Student>();
??stuList.add(stu);
??stuList.add(stu2);
??School school = new School();
??school.setSchool(stuList);
??
??try {
???JAXBContext jc = JAXBContext.newInstance(School.class);
???Marshaller marshall = jc.createMarshaller();
???marshall.setProperty(Marshaller.JAXB_ENCODING,"UTF-8");
???marshall.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT,Boolean.TRUE);
???StringWriter writer = new StringWriter();
???marshall.marshal(school,writer);
???System.out.println(writer);
??} catch (JAXBException e) {
???// TODO Auto-generated catch block
???e.printStackTrace();
??}
??
?}
//不知为何会有<school>标签
原来默认是以private List<Student> school 字段名标识的，而不是以List中标注的根元素名标志的。
?
--------------如果想拒绝别人的批评，那就只能做个无脑无能无为无知的人--------------------
