Java Parse Json对象,包含要映射到字符串到字符串数组的字符串映射
我试图解析一个json字符串,它是一个包含字符串键映射到字符串数组的字符串键映射的对象。我已经将json字符串简化为我正在努力解析的对象,但实际上是嵌入到其他对象中的对象 Json: 我创建了一个简单的测试类来测试解析这个特定对象:Java Parse Json对象,包含要映射到字符串到字符串数组的字符串映射,java,json,jackson,Java,Json,Jackson,我试图解析一个json字符串,它是一个包含字符串键映射到字符串数组的字符串键映射的对象。我已经将json字符串简化为我正在努力解析的对象,但实际上是嵌入到其他对象中的对象 Json: 我创建了一个简单的测试类来测试解析这个特定对象: import java.io.IOException; import com.fasterxml.jackson.databind.ObjectMapper; public class JsonParseTest { public static void
import java.io.IOException;
import com.fasterxml.jackson.databind.ObjectMapper;
public class JsonParseTest {
public static void main(String[] args) {
String json = "{\"restrictions\":{\"master\":\"bsu.school\",\"conditions\":{\"HCI\":[\"CMP\",\"HRM\",\"PUBL\",\"CRA\",\"FTV\",\"AGS\",\"MAS\",\"MCOM\",\"BMPP\",\"BUS\",\"CUS\",\"FSS\",\"PHET\",\"HIST\",\"ENL\",\"STR\",\"CWR\",\"STAF\"],\"MPA\":[\"MAPE\",\"MAPS\",\"BACC\",\"MASW\",\"BAMU\",\"BAPA\",\"MAPA\",\"MATY\",\"MACM\",\"BADR\",\"KIST\",\"BADA\",\"PARM\",\"BAP\",\"BACM\",\"BATP\",\"MACO\",\"BACMT\",\"CSMT\",\"BAAM\"],\"BSAD\":[\"BSAD3\",\"BSAD1\",\"BSAD2\"]}}}";
ObjectMapper objectMapper = new ObjectMapper();
// Convert the json string to Restrictions object
try {
RestrictionsContainer restrictionsContainer = objectMapper.readValue(json, RestrictionsContainer.class);
System.out.println("restrictionsContainer " + restrictionsContainer);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
限制容器类别:
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties(ignoreUnknown = true)
public class RestrictionsContainer {
private Restrictions restrictions = null;
/**
* @return the restrictions
*/
public Restrictions getRestrictions() {
return restrictions;
}
/**
* @param restrictions the restrictions to set
*/
public void setRestrictions(Restrictions restrictions) {
this.restrictions = restrictions;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("RestrictionsContainer [restrictions=").append(restrictions).append("]");
return builder.toString();
}
}
限制类别:
import java.util.HashMap;
import java.util.Map;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties(ignoreUnknown = true)
public class Restrictions {
private String master = null;
private Map<String, Object> conditions = new HashMap<>();
/**
* @return the master
*/
public String getMaster() {
return master;
}
/**
* @param master the master to set
*/
public void setMaster(String master) {
this.master = master;
}
/**
* @return the conditions
*/
public Map<String, Object> getConditions() {
return conditions;
}
/**
* @param conditions the conditions to set
*/
public void setConditions(Map<String, Object> conditions) {
this.conditions = conditions;
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
StringBuilder builder = new StringBuilder();
builder.append("Restrictions [master=").append(master).append(", conditions=").append(conditions).append("]");
return builder.toString();
}
}
条件对象的字符串键是动态的,因此我不能使用对象
定义条件对象的正确方法是什么?您定义的条件类型错误:
private Map<String, Map<String,List<String>>> conditions = new HashMap<>(); // WRONG
更改此选项,您的代码就可以正常工作。您的代码没有问题,而是Jackson无法“直接引用类型”。类型引用返回表示该类表示的实体(类、接口、基元类型或void)的直接超类的类型 如果超类是参数化类型,则返回的type对象必须准确反映源代码中使用的实际类型参数 您的修复应该如下所示:
Map myObjects=mapper.readValue(mapData,新类型引用
private Map<String, Map<String,List<String>>> conditions = new HashMap<>();
com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `java.util.LinkedHashMap` out of START_ARRAY token
at [Source: (String)"{"restrictions":{"master":"bsu.school","conditions":{"HCI":["CMP","HRM","PUBL","CRA","FTV","AGS","MAS","MCOM","BMPP","BUS","CUS","FSS","PHET","HIST","ENL","STR","CWR","STAF"],"MPA":["MAPE","MAPS","BACC","MASW","BAMU","BAPA","MAPA","MATY","MACM","BADR","KIST","BADA","PARM","BAP","BACM","BATP","MACO","BACMT","CSMT","BAAM"],"BSAD":["BSAD3","BSAD1","BSAD2"]}}}"; line: 1, column: 60] (through reference chain: RestrictionsContainer["restrictions"]->Restrictions["conditions"]->java.util.LinkedHashMap["HCI"])
at com.fasterxml.jackson.databind.exc.MismatchedInputException.from(MismatchedInputException.java:63)
at com.fasterxml.jackson.databind.DeserializationContext.reportInputMismatch(DeserializationContext.java:1342)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1138)
at com.fasterxml.jackson.databind.DeserializationContext.handleUnexpectedToken(DeserializationContext.java:1092)
at com.fasterxml.jackson.databind.deser.std.StdDeserializer._deserializeFromEmpty(StdDeserializer.java:599)....
private Map<String, Map<String,List<String>>> conditions = new HashMap<>(); // WRONG
private Map<String, List<String>> conditions;