我发现很多文章描述了如何将 XML 元素序列解组到 HashMap(只要它们位于“父”元素内)。但是,我无法将此与直接在根元素下的子元素一起使用!
选项 1 - 有效:
<?xml version="1.0" encoding="UTF-8"?>
<checks>
<checks>
<check key="check1"/>
<check key="check2"/>
...
</checks>
</checks>
选项 2 - 是否not work:
<?xml version="1.0" encoding="UTF-8"?>
<checks>
<check key="check1"/>
<check key="check2"/>
...
</checks>
Checks:
package com.foo.conf;
import java.util.Map;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
@XmlRootElement(name="checks")
public class Checks {
@XmlJavaTypeAdapter(ChecksAdapter.class)
@XmlElement(name="checks")
public Map<String, Check> checkMap;
}
Check:
package com.foo.conf;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlValue;
public class Check {
@XmlAttribute public String key;
@XmlValue public String description;
public Check() { }
public Check(String key) {
this.key = key;
}
public String getCheckKey() {
return this.key;
}
}
检查地图类型:
package com.foo.conf;
import java.util.List;
import javax.xml.bind.annotation.XmlElement;
class CheckMapType {
@XmlElement(name="check")
public List<Check> checkList; // = new ArrayList<Check>();
}
检查适配器:
package com.foo.conf;
import java.util.HashMap;
import java.util.Map;
import javax.xml.bind.annotation.adapters.XmlAdapter;
final class ChecksAdapter extends XmlAdapter<CheckMapType, Map<String, Check>> {
@Override
public CheckMapType marshal(Map<String, Check> arg0) throws Exception {
return null;
}
@Override
public Map<String, Check> unmarshal(CheckMapType arg0) throws Exception {
System.out.println("u: " + arg0.checkList.size());
Map<String, Check> map = new HashMap<String, Check>();
for (Check check : arg0.checkList) {
System.out.println(check);
map.put(check.key, check);
}
return map;
}
}
这是(一些虚拟测试行)我生成类/调用解组的方式:
JAXBContext jc = JAXBContext.newInstance(Checks.class);
Unmarshaller u = jc.createUnmarshaller();
Checks c = (Checks) u.unmarshal(new File("checks.xml"));
System.out.println(c.checkMap.size());
知道如何让选项 #2 发挥作用吗?它在使用列表而不是映射时有效,但我需要 HashMap,因为我必须通过给定的键访问对象......
任何提示非常感谢!