Apache CXF实战之三 Map类型绑定

在CXF中，如果Web Service返回类型是Map的时候，比如方法签名如下

 

@WebMethod
@WebResult Map<String, User> getUserMap();

此时如果运行程序会得到类似下面的异常

...
Caused by: com.sun.xml.bind.v2.runtime.IllegalAnnotationsException: 2 counts of IllegalAnnotationExceptions
java.util.Map is an interface, and JAXB can't handle interfaces.
    this problem is related to the following location:
        at java.util.Map
        at private java.util.Map com.googlecode.garbagecan.cxfstudy.type.sample2.jaxws_asm.GetUserMapResponse._return
        at com.googlecode.garbagecan.cxfstudy.type.sample2.jaxws_asm.GetUserMapResponse
java.util.Map does not have a no-arg default constructor.
    this problem is related to the following location:
        at java.util.Map
        at private java.util.Map com.googlecode.garbagecan.cxfstudy.type.sample2.jaxws_asm.GetUserMapResponse._return
        at com.googlecode.garbagecan.cxfstudy.type.sample2.jaxws_asm.GetUserMapResponse
    at com.sun.xml.bind.v2.runtime.IllegalAnnotationsException$Builder.check(IllegalAnnotationsException.java:102)
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl.getTypeInfoSet(JAXBContextImpl.java:472)
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl.<init>(JAXBContextImpl.java:302)
    at com.sun.xml.bind.v2.runtime.JAXBContextImpl$JAXBContextBuilder.build(JAXBContextImpl.java:1136)
    at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:154)
    at com.sun.xml.bind.v2.ContextFactory.createContext(ContextFactory.java:121)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at javax.xml.bind.ContextFinder.newInstance(Unknown Source)
    at javax.xml.bind.ContextFinder.newInstance(Unknown Source)
    at javax.xml.bind.ContextFinder.find(Unknown Source)
    at javax.xml.bind.JAXBContext.newInstance(Unknown Source)
    at org.apache.cxf.jaxb.JAXBDataBinding.createContext(JAXBDataBinding.java:560)
    at org.apache.cxf.jaxb.JAXBDataBinding.createJAXBContextAndSchemas(JAXBDataBinding.java:500)
    at org.apache.cxf.jaxb.JAXBDataBinding.initialize(JAXBDataBinding.java:320)
    ... 25 more
...

如果把方法签名改为如下时

 

 

@WebMethod
@WebResult HashMap<String, User> getUserMap();

运行程序会发现返回的结果总是一个空的HashMap。

 

 

对于以上问题，此时需要对Map类型做一下数据绑定或者说转换，看下面详细例子

1. 首先是一个实体类

 

package com.googlecode.garbagecan.cxfstudy.type.sample2;

public class User {
    private String id;
    private String name;
    private String password;
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
}

2. 对Map类型做转换的类和适配器类

 

 

package com.googlecode.garbagecan.cxfstudy.type.sample2;

import java.util.HashMap;
import java.util.Map;

import javax.xml.bind.annotation.adapters.XmlAdapter;

public class MapAdapter extends XmlAdapter<MapConvertor, Map<String, Object>> {

    @Override
    public MapConvertor marshal(Map<String, Object> map) throws Exception {
        MapConvertor convertor = new MapConvertor();
        for (Map.Entry<String, Object> entry : map.entrySet()) {
            MapConvertor.MapEntry e = new MapConvertor.MapEntry(entry);
            convertor.addEntry(e);
        }
        return convertor;
    }

    @Override
    public Map<String, Object> unmarshal(MapConvertor map) throws Exception {
        Map<String, Object> result = new HashMap<String, Object>();
        for (MapConvertor.MapEntry e : map.getEntries()) {
            result.put(e.getKey(), e.getValue());
        }
        return result;
    }
}

package com.googlecode.garbagecan.cxfstudy.type.sample2;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import javax.xml.bind.annotation.XmlAccessType;
import javax.xml.bind.annotation.XmlAccessorType;
import javax.xml.bind.annotation.XmlType;

@XmlType(name = "MapConvertor")
@XmlAccessorType(XmlAccessType.FIELD)
public class MapConvertor {
    private List<MapEntry> entries = new ArrayList<MapEntry>();

    public void addEntry(MapEntry entry) {
        entries.add(entry);
    }

    public List<MapEntry> getEntries() {
        return entries;
    }

    public static class MapEntry {

        private String key;

        private Object value;

        public MapEntry() {
            super();
        }

        public MapEntry(Map.Entry<String, Object> entry) {
            super();
            this.key = entry.getKey();
            this.value = entry.getValue();
        }

        public MapEntry(String key, Object value) {
            super();
            this.key = key;
            this.value = value;
        }

        public String getKey() {
            return key;
        }

        public void setKey(String key) {
            this.key = key;
        }

        public Object getValue() {
            return value;
        }

        public void setValue(Object value) {
            this.value = value;
        }
    }
}

3. 下面是WebService接口类，注意其中的@XmlJavaTypeAdapter注解部分

 

 

package com.googlecode.garbagecan.cxfstudy.type.sample2;

import java.util.List;
import java.util.Map;

import javax.jws.WebMethod;
import javax.jws.WebResult;
import javax.jws.WebService;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;

@WebService
public interface UserService {

    @WebMethod
    @WebResult List<User> getUserList();

    @WebMethod
    @XmlJavaTypeAdapter(MapAdapter.class)
    @WebResult Map<String, User> getUserMap();
}

4. WebService接口实现类

 

 

package com.googlecode.garbagecan.cxfstudy.type.sample2;

import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

public class UserServiceImpl implements UserService {

    public List<User> getUserList() {
        List<User> userList = new ArrayList<User>();
        for (int i = 0; i < 10; i++) {
            User user = new User();
            user.setId("" + i);
            user.setName("user_" + i);
            user.setPassword("password_" + i);
            userList.add(user);
        }
        return userList;
    }

    public Map<String, User> getUserMap() {
        Map<String, User> userMap = new LinkedHashMap<String, User>();
        for (int i = 0; i < 10; i++) {
            User user = new User();
            user.setId("" + i);
            user.setName("user_" + i);
            user.setPassword("password_" + i);
            userMap.put(user.getId(), user);
        }
        return userMap;
    }
}

5. 最后是一个单元测试类

 

 

package com.googlecode.garbagecan.cxfstudy.type.sample2;

import java.util.List;
import java.util.Map;

import javax.xml.ws.Endpoint;

import org.apache.cxf.jaxws.JaxWsProxyFactoryBean;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;

public class UserServiceTest {

    private static final String address = "http://localhost:9000/ws/type/sample2/userService";

    private UserService userService;

    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
        Endpoint.publish(address, new UserServiceImpl());
    }

    @Before
    public void setUp() throws Exception {
        JaxWsProxyFactoryBean factoryBean = new JaxWsProxyFactoryBean();
        factoryBean.setAddress(address);
        factoryBean.setServiceClass(UserService.class);
        Object obj = factoryBean.create();
        userService = (UserService)obj;
    }

    @After
    public void tearDown() throws Exception {
        userService = null;
    }

    @Test
    public void testGetUserList() {
        Assert.assertNotNull(userService);
        List<User> users = userService.getUserList();
        Assert.assertNotNull(users);
        Assert.assertEquals(10, users.size());
    }

    @Test
    public void testGetUserMap() {
        Assert.assertNotNull(userService);
        Map<String, User> users = userService.getUserMap();
        Assert.assertNotNull(users);
        Assert.assertEquals(10, users.size());
    }

}

6. 运行单元测试类验证上面的实现。