如何用 java 处理 xml 和 json ?

java解析处理xml和json. 应该都有很多实现的方式. 这里总结其中一种方式.

使用 dom4j 生成和解析 xml

<!--增加解析xml依赖-->
<dependency>
    <groupId>org.dom4j</groupId>
    <artifactId>dom4j</artifactId>
    <version>2.1.1</version>
</dependency>

生成xml

右侧截图为代码执行结果

@Test
public void Test01() {
    try{
        Document document = DocumentHelper.createDocument();
        //默认是utf-8 如果是其他编码需要手动指定
        //document.setXMLEncoding("gb2312");
        Element root = DocumentHelper.createElement("MCF");
        document.setRootElement(root);

        root.addAttribute("Name", "处方");
        root.addAttribute("OprType", "1");
        root.addElement("MCF.0").setText("");
        root.addElement("MCF.11").setText("11");
        Element drugList = root.addElement ("MCF.50.GRP");

        for (int i = 0; i < 3 ; i++) {
            Element d0 = drugList.addElement("MCF.50");
            d0.addElement("MCF.54").setText("54-" + i);
            d0.addElement("MCF.55").setText("55-" + i);
        }

        System.out.println(document.asXML());

    }catch (Exception e){
        e.printStackTrace();
    }
}

解析生成的xml

@Test
public void Test02() throws DocumentException {
    String xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?> <MCF Name=\"处方\" OprType=\"1\"> <MCF.0/> <MCF.11>11</MCF.11> <MCF.50.GRP> <MCF.50> <MCF.54>54-0</MCF.54> <MCF.55>55-0</MCF.55> </MCF.50> <MCF.50> <MCF.54>54-1</MCF.54> <MCF.55>55-1</MCF.55> </MCF.50> <MCF.50> <MCF.54>54-2</MCF.54> <MCF.55>55-2</MCF.55> </MCF.50> </MCF.50.GRP> </MCF>";
    Document doc = DocumentHelper.parseText(xml);
    System.out.println(doc.getRootElement().elementText("MCF.11"));
    List<Element> list = doc.getRootElement().element("MCF.50.GRP").elements("MCF.50");
    for (Element e : list) {
        System.out.println(e.elementText("MCF.54") + " " + e.elementText("MCF.55"));
    }

}

使用jackson解析json

<!--增加解析json依赖-->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.13.1</version>
    </dependency>

生成json

生成一般不会直接生成. 会新建一个响应类创建一个响应对象. 然后给对象赋值. 再转成json

右侧截图为代码执行结果

@Test
    public void Test05() throws Exception {
        ObjectMapper mapper = new ObjectMapper();
        ObjectNode rootNode = mapper.createObjectNode(); //跟节点
        ObjectNode childNode1 = mapper.createObjectNode();//第一层
        ObjectNode childNode2 = mapper.createObjectNode();//第二层

        childNode1.put("MCF.0","");
        childNode1.put("MCF.11","11");

        ArrayNode arrayNode = mapper.createArrayNode();
        for (int i = 0; i < 3 ; i++) {
            ObjectNode childNode50 = mapper.createObjectNode();
            childNode50.put("MCF.54","54-" + i);
            childNode50.put("MCF.55","55-" + i);
            arrayNode.add(childNode50);
        }

        childNode2.set("MCF.50",arrayNode);
        childNode1.set("MCF.50.GRP",childNode2);

        rootNode.set("MCF",childNode1);
        mapper.writeValueAsString(rootNode);

        String jsonString = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(rootNode);
        System.out.println(jsonString);
    }

解析生成的json

@Test
public void Test06() throws Exception {
    String json = "{ \"MCF\" : { \"MCF.0\" : \"\", \"MCF.11\" : \"11\", \"MCF.50.GRP\" : { \"MCF.50\" : [ { \"MCF.54\" : \"54-0\", \"MCF.55\" : \"55-0\" }, { \"MCF.54\" : \"54-1\", \"MCF.55\" : \"55-1\" }, { \"MCF.54\" : \"54-2\", \"MCF.55\" : \"55-2\" } ] } } }";

    JsonNode root = mapper.readTree(json);

    System.out.println(root.get("MCF").get("MCF.11").asText());

    JsonNode prescriptions = root.get("MCF").get("MCF.50.GRP").get("MCF.50");

    for (int i = 0; i <= prescriptions.size() - 1 ; i++) {
        JsonNode drugs = prescriptions.get(i);
        System.out.println(drugs.get("MCF.54").asText() + " " + drugs.get("MCF.55").asText());
    }
}

hutool 解析

对象转json

//对象
Student beanString = new Student(1, 1, 1, "张三");

//集合
List<Student> list = new ArrayList<>();
list.add(new Student(1, 1, 1, "张三"));
list.add(new Student(1, 1, 2, "李四"));
list.add(new Student(1, 1, 3, "王五"));

System.out.println("JSONUtil.toJsonStr(beanString) = " + JSONUtil.toJsonStr(beanString));
System.out.println("JSONUtil.toJsonStr(list) = " + JSONUtil.toJsonStr(list));

对象转格式化的JSON

JSONUtil.toJsonPrettyStr(object);

System.out.println("JSONUtil.toJsonPrettyStr(sortedMap) = "
 + JSONUtil.toJsonPrettyStr(sortedMap));

json解析

String html = "{\"name\":\"Something must have been changed since you leave\"}";
JSONObject jsonObject = JSONUtil.parseObj(html);
System.out.println("jsonObject.getStr(\"name\") = " + jsonObject.getStr("name"));

XML字符串转为JSONObject

String s = "<sfzh>123</sfzh><sfz>456</sfz><name>aa</name><gender>1</gender>";
JSONObject json = JSONUtil.parseFromXml(s);
System.out.println("json.get(\"sfzh\") = " + json.get("sfzh"));
System.out.println("json.get(\"name\") = " + json.get("name"));

json.get("sfzh") = 123
json.get("name") = aa

JSON转换为XML

final JSONObject put = JSONUtil.createObj()
        .set("aaa", "你好")
        .set("键2", "test");

// <aaa>你好</aaa><键2>test</键2>
final String s = JSONUtil.toXmlStr(put);
System.out.println("s = " + s);

JSON转Bean

String json = "{\"ADT\":[[{\"BookingCode\":[\"N\",\"N\"]}]]}";
Price price = JSONUtil.toBean(json, Price.class);
System.out.println("price = " + price);