xmap使用实例

例如，我要读入这样的xml格式：

【待读入的xml文件】

<?xml version="1.0" encoding="GBK"?>
<operations>
    <operation op="ADD">
        <topicmessage>
            <string>100, 101</string>
            <string>200, 201</string>
        </topicmessage>
        
        <context>
            <string>mysqlcluster, 100</string>
            <string>mysqlcluster, 200</string>
        </context>
    </operation>
    
</operations>

那么，很显然，operations是什么？里面的operation又是什么？别着急，来了。

【xml映射为的java类们】

@XObject("operations")
public class Operations {
    
    @XNodeList(value="operation", type=ArrayList.class, componentType=Operation.class)
    private List<Operation> operations;

    public List<Operation> getOperations() {
        return operations;
    }

    public void setOperations(List<Operation> operations) {
        this.operations = operations;
    }
    
}

@XObject
public class Operation {
    @XNode("@op")
    private String       op;

    @XNodeList(value = "topicmessage/string", type = ArrayList.class, componentType = String.class)
    private List<String> topicmessages        = Collections.emptyList(); ;

    @XNodeList(value = "context/string", type = ArrayList.class, componentType = String.class)
    private List<String> contexts             = Collections.emptyList(); ;

    @XNodeList(value = "cluster/string", type = ArrayList.class, componentType = String.class)
    private List<String> clusters             = Collections.emptyList(); ;

    public String getOp() {
        return op;
    }

    public void setOp(String op) {
        this.op = op;
    }

    public List<String> getTopicmessages() {
        return topicmessages;
    }

    public void setTopicmessages(List<String> topicmessages) {
        this.topicmessages = topicmessages;
    }

    public List<String> getContexts() {
        return contexts;
    }

    public void setContexts(List<String> contexts) {
        this.contexts = contexts;
    }

    public List<String> getClusters() {
        return clusters;
    }

    public void setClusters(List<String> clusters) {
        this.clusters = clusters;
    }
}

好，已经建好了xml-class间的映射关系。可以开始读了：

【xmap读取xml文件】

public final List<Operation> readXML() {
        XMap xmap = new XMap();
        xmap.register(Operations.class);

        // 加载文件
        Object[] result = null;
        try {
            URL url = new File(dir, filename).toURL();
            result = (Object[]) xmap.loadAll(url);
        } catch (Exception e) {
            String msg = "解析" + filename + "时发生错误";
            LOGGER.error(msg, e);
            throw new PairFileException(msg, e);
        }
        if (result.length == 0) {
            return null;
        } else {
            Object element = result[0];
            Operations c = (Operations) element;
            return c.getOperations();
        }
    }

好了，读讲完了。那写呢？我现在想生成这样格式的xml文件，可以吗，怎么做呢。假设你的operation和operations内容，都已经准备好了，那么：

【xmap写xml文件】

        XMap xmap = new XMap();
        xmap.register(Operations.class);
        List<String> filters = new ArrayList<String>();
        String result = xmap.asXmlString(myOperations, "GBK", filters, true);

xmap语法，可参见附件。