Springboot-将JSON转换为JAVA
我需要从RESTAPI中获取货币汇率,并将JSON响应转换为Java类。API将给我以下响应:-Springboot-将JSON转换为JAVA,json,spring-boot,resttemplate,Json,Spring Boot,Resttemplate,我需要从RESTAPI中获取货币汇率,并将JSON响应转换为Java类。API将给我以下响应:- { "USD_INR": { "val": 71.884966 } } 代码如下所示: @RestController public class MainController { @Autowired private RestTemplate restTemplate; @GetMapping("/hello") public float hel
{
"USD_INR": {
"val": 71.884966
}
}
代码如下所示:
@RestController
public class MainController {
@Autowired
private RestTemplate restTemplate;
@GetMapping("/hello")
public float hello(){
ExchangeRate exchangeRate = restTemplate.getForObject("https://free.currencyconverterapi.com/api/v6/convert?q=Source_Target&compact=y",ExchangeRate.class);
return exchangeRate.getSource_Target().getVal();
}
}
-
在执行REST调用之后,我得到null异常。一无所获。我在这里搞不清楚这个问题。请提供帮助您可以使用它轻松地从json生成java bean
JSON:
}
对应的Java bean:
-----------------------------------com.example.Example.java-----------------------------------
package com.example;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonAnySetter;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({
"USD_INR"
})
public class Example implements Serializable
{
@JsonProperty("USD_INR")
private USDINR uSDINR;
@JsonIgnore
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
private final static long serialVersionUID = -932753391825750904L;
@JsonProperty("USD_INR")
public USDINR getUSDINR() {
return uSDINR;
}
@JsonProperty("USD_INR")
public void setUSDINR(USDINR uSDINR) {
this.uSDINR = uSDINR;
}
public Example withUSDINR(USDINR uSDINR) {
this.uSDINR = uSDINR;
return this;
}
@JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
@JsonAnySetter
public void setAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
}
public Example withAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
return this;
}
}
-----------------------------------com.example.USDINR.java-----------------------------------
package com.example;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonAnySetter;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({
"val"
})
public class USDINR implements Serializable
{
@JsonProperty("val")
private Double val;
@JsonIgnore
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
private final static long serialVersionUID = -6384976748235176082L;
@JsonProperty("val")
public Double getVal() {
return val;
}
@JsonProperty("val")
public void setVal(Double val) {
this.val = val;
}
public USDINR withVal(Double val) {
this.val = val;
return this;
}
@JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
@JsonAnySetter
public void setAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
}
public USDINR withAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
return this;
}
}
------------------------------------com.example.example.java-----------------------------------
包com.example;
导入java.io.Serializable;
导入java.util.HashMap;
导入java.util.Map;
导入com.fasterxml.jackson.annotation.JsonAnyGetter;
导入com.fasterxml.jackson.annotation.JsonAnySetter;
导入com.fasterxml.jackson.annotation.JsonIgnore;
导入com.fasterxml.jackson.annotation.JsonInclude;
导入com.fasterxml.jackson.annotation.JsonProperty;
导入com.fasterxml.jackson.annotation.JsonPropertyOrder;
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({
“美元卢比”
})
公共类示例实现了可序列化
{
@JsonProperty(“美元卢比”)
私人股本美元卢比美元卢比;
@杰索尼奥雷
私有映射additionalProperties=new HashMap();
私有最终静态长serialVersionUID=-932753391825750904L;
@JsonProperty(“美元卢比”)
公共USDINR getUSDINR(){
返回美元卢比;
}
@JsonProperty(“美元卢比”)
公共作废设置USDINR(USDINR USDINR){
这是。uSDINR=uSDINR;
}
以USDINR(USDINR USDINR)作为公共示例{
这是。uSDINR=uSDINR;
归还这个;
}
@JsonAnyGetter
公共映射getAdditionalProperties(){
返回此。附加属性;
}
@JSONANYSETER
public void setAdditionalProperty(字符串名称、对象值){
this.additionalProperties.put(名称、值);
}
带有AdditionalProperty(字符串名称、对象值)的公共示例{
this.additionalProperties.put(名称、值);
归还这个;
}
}
-----------------------------------com.example.USDINR.java-----------------------------------
包com.example;
导入java.io.Serializable;
导入java.util.HashMap;
导入java.util.Map;
导入com.fasterxml.jackson.annotation.JsonAnyGetter;
导入com.fasterxml.jackson.annotation.JsonAnySetter;
导入com.fasterxml.jackson.annotation.JsonIgnore;
导入com.fasterxml.jackson.annotation.JsonInclude;
导入com.fasterxml.jackson.annotation.JsonProperty;
导入com.fasterxml.jackson.annotation.JsonPropertyOrder;
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonPropertyOrder({
“瓦尔”
})
公共类USDINR实现可序列化
{
@JsonProperty(“val”)
私人双重增值税;
@杰索尼奥雷
私有映射additionalProperties=new HashMap();
私有最终静态长serialVersionUID=-6384976748235176082L;
@JsonProperty(“val”)
公共双getVal(){
返回val;
}
@JsonProperty(“val”)
公共无效设置值(双值){
this.val=val;
}
带val的公共美元卢比(双倍val){
this.val=val;
归还这个;
}
@JsonAnyGetter
公共映射getAdditionalProperties(){
返回此。附加属性;
}
@JSONANYSETER
public void setAdditionalProperty(字符串名称、对象值){
this.additionalProperties.put(名称、值);
}
公共USDINR withAdditionalProperty(字符串名称、对象值){
this.additionalProperties.put(名称、值);
归还这个;
}
}
您的ExchangeRate类应为:
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class ExchangeRate {
@JsonProperty("USD_INR")
Source_Target SourceTargetObject;
public Source_Target getSource_Target() {
return SourceTargetObject;
}
public void setSource_Target(Source_Target SourceTargetObject) {
this.SourceTargetObject = SourceTargetObject;
}
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class Source_Target {
@JsonProperty("val")
private float val;
public float getVal() {
return val;
}
public void setVal(float val) {
this.val = val;
}
}
那么您的源\目标类应该是:
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class ExchangeRate {
@JsonProperty("USD_INR")
Source_Target SourceTargetObject;
public Source_Target getSource_Target() {
return SourceTargetObject;
}
public void setSource_Target(Source_Target SourceTargetObject) {
this.SourceTargetObject = SourceTargetObject;
}
@JsonInclude(JsonInclude.Include.NON_NULL)
@JsonIgnoreProperties(ignoreUnknown = true)
public class Source_Target {
@JsonProperty("val")
private float val;
public float getVal() {
return val;
}
public void setVal(float val) {
this.val = val;
}
}
请注意您的类命名约定。我将
Source\u Target
重命名为SourceTarget
,以遵循Java命名约定您可以创建一个自定义映射:
public class ExchangeRate extends HashMap<String, ExchangeRateValue> implements Serializable {
}
public class ExchangeRateValue implements Serializable {
private float val;
public float getVal() {
return val;
}
public void setVal(float val) {
this.val = val;
}
}
您能否将确切的
NullPointerException
堆栈跟踪发布到您的问题?@JsonProperty(“USD_INR”)-不能这样给出,因为属性随源和目标货币的不同而变化。@JsonProperty(“USD_INR”)-不能这样给出,因为属性随源和目标货币的不同而变化。。
ExchangeRate exchangeRate = restTemplate.getForObject("https://free.currencyconverterapi.com/api/v6/convert?q=Source_Target&compact=y", ExchangeRate.class);
float data = exchangeRate.get("USD_INR").getVal();