使用ObjectMapper java API解析JSON字符串

处理这些场景的最佳方法是为json创建一个匹配的pojo。这样,你就可以灵活地处理这些数据。

创建这样的类

public class Someclass {

    private String customerId;

    Map<String, String> nameIdmap;

    public Map<String, String> getNameIdmap() {
        return nameIdmap;
    }

    public void setNameIdmap(Map<String, String> nameIdmap) {
        this.nameIdmap = nameIdmap;
    }

    public Someclass() {
    }

    public String getCustomerId() {
        return customerId;
    }

    public void setCustomerId(String customerId) {
        this.customerId = customerId;
    }
}

这段代码将把json转换成SomeClass类

String json = "<copy paste your json here>";
Someclass someclass = objectMapper.readValue(json, Someclass.class);
String s = someclass.getNameIdmap().get("10.2.1.0");
String[] splits = s.split(" ");
String productType = splits[0].split("=")[1];
String id = splits[1].split("=")[1];
System.out.println(productType + "  " + id);

您可以尝试自定义反序列化程序,如下所示

这是一个POJO,代表一个ID和一个String和IPItem的映射

public class SOItem {
    @Override
    public String toString() {
        return "SOItem [id=" + id + ", map=" + map + "]";
    }
    String id;
    Map<String, SOIPItem> map = new HashMap();

    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public Map<String, SOIPItem> getMap() {
        return map;
    }
    public void setMap(Map<String, SOIPItem> map) {
        this.map = map;
    }
}

2。创建IPItem类

public class SOIPItem {
    private String type;
    private String id;

    public String getType() {
        return type;
    }
    public void setType(String type) {
        this.type = type;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }

    @Override
    public String toString() {
        return "SOIPItem [type=" + type + ", id=" + id + "]";
    }
    public SOIPItem(String type, String id) {
        super();
        this.type = type;
        this.id = id;
    }
}

三。创建自定义反序列化程序

import java.io.IOException;
import java.util.Iterator;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.ObjectCodec;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;

public class SOCustDeser extends StdDeserializer<SOItem> {

    public SOCustDeser() {
        this(null);
    }
    public SOCustDeser(Class<?> vc) {
        super(vc);
    }

    /**
     * 
     */
    private static final long serialVersionUID = -394222274225082713L;

    @Override
    public SOItem deserialize(JsonParser parser, DeserializationContext arg1)
            throws IOException, JsonProcessingException {
        SOItem soItem = new SOItem();

        ObjectCodec codec = parser.getCodec();
        JsonNode node = codec.readTree(parser);

        soItem.setId(node.get("customerId").asText());

        JsonNode idmap = node.get("nameIdmap");
        Iterator<String> fieldNames = idmap.fieldNames();
        while(fieldNames.hasNext()) {
          String ip = fieldNames.next();
          String textValue = idmap.get(ip).asText();

          Pattern p = Pattern.compile("(.*?)=(.*?),(.*?)(\\d+)");
          Matcher m = p.matcher(textValue);
          if (m.find()) {
              soItem.map.put(ip, new SOIPItem(m.group(2), m.group(4)));
          }
        }

        return soItem;
    }
}

四。测试类

import java.io.File;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;

public class MicsTest {
    public static void main(String[] args) throws Exception {
        ObjectMapper om = new ObjectMapper();
        SimpleModule sm = new SimpleModule();
        sm.addDeserializer(SOItem.class, new SOCustDeser());
        om.registerModule(sm);

        SOItem item = om.readValue(new File("c:\\temp\\test.json"), SOItem.class);

        System.out.println(item);
    }
}

SOItem[id=dummy1,map={10.2.1.0=SOIPItem[type=null,id=123],10.2.1.3=SOIPItem[type=null,id=456],10.2.1.5=SOIPItem[type=null,id=193],10.2.1.4=SOIPItem[type=null,id=789]}

作为迭代器,可以通过nameIdmap.get field names获取字段名。然后可以这样迭代:

...
Iterator<String> fieldNames = idmap.getFieldNames();
while(fieldNames.hasNext()) {
  String ip = fieldNames.next();
  String textValue = idmap.get(ip).getTextValue()
  System.out.println(ip + ":" + textValue);
}

Pattern p = Pattern.compile("ID=(\\d+)");
Matcher m = p.matcher(textValue);
if(m.find()) {
  System.out.println(ip + ":" + m.group(1));
}