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我一直在使用Jackson编写Rest服务来提取响应值内的名称和sizeFromStorage。尝试读取嵌套在JSON中的数组中的值
我创建了下面的类，试图做到这一点：
import java.util.List;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties(value = {"status", "header"})
public class Vaults {
private List<Object> response;
public Vaults(){
}
public Vaults(List<Object> response){
this.response = response;
}
public List<Object> getResponse(){
return response;
}
public void setResponse(List<Object> response) {
this.response = response;
}
@Override
public String toString() {
return "" + response;
}
}
import java.io.IOException;
import java.util.List;
import java.util.ArrayList;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.type.CollectionType;
import java.io.InputStream;
public class JacksonObjectModelTest {
public static void main(String[] args) throws IOException {
String jsonFileName = "/JsonRead/json.json";
List<Vaults> emps = new JacksonObjectModelTest().getVaultList(jsonFileName);
System.out.println(emps.toString());
}
public ArrayList<Vaults> getVaultList(String jsonFileName) throws IOException {
//read json file data to String
InputStream inputStream = getClass().getResourceAsStream(jsonFileName);
//create ObjectMapper instance
ObjectMapper objectMapper = new ObjectMapper().enable(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY);
//convert json string to object
CollectionType collectionType = objectMapper.getTypeFactory().constructCollectionType(List.class, Vaults.class);
ArrayList<Vaults> emps = objectMapper.readValue(inputStream, collectionType);
return (ArrayList<Vaults>) emps;
}
}
{
"status": "ok",
"header": {
"now": 1491545894581,
"status": "ok",
"requestId": "WOcvJsCoAmoAAESbkBYAAAB5"
},
"response": {
"vault": [
{
"id": 20,
"name": "Apple",
"description": "",
"sizeFromStorage": 95957225298,
"storagePools": [
{
"storagePool": {
"id": 1,
"name": "storage-pool1",
"sizeFromStorage": 95957225298,
"generations": [
{
"generation": {
"sequence": 0
}
}
]
}
}
]
},
{
"id": 21,
"name": "Banana",
"description": "",
"sizeFromStorage": 98957268244,
"storagePools": [
{
"storagePool": {
"id": 2,
"name": "storage-pool1",
"sizeFromStorage": 98957268244,
"generations": [
{
"generation": {
"sequence": 0
}
}
]
}
}
]
},
]
}
}
输出我从这个得到的是：
[[{vaults=[{id=20, name=Apple, description=, sizeFromStorage=95957225298, storagePools=[{storagePool={id=1, name=storage-pool1, sizeFromStorage=5043, estimateUsableTotalLogicalSizeFromStorage=95957225298, generations=[{generation={sequence=0}}]}}]}, {id=20, name=Apple, description=, sizeFromStorage=95957225298, storagePools=[{storagePool={id=1, name=storage-pool1, sizeFromStorage=5043, estimateUsableTotalLogicalSizeFromStorage=95957225298, generations=[{generation={sequence=0}}]}}]}]]
不过，我想要做的是名称和sizeFromStorage值。到目前为止，我已经设法排除了前三个值。不幸的是我现在陷入困境，因为我对休息服务或阅读JSON不是很熟悉。有什么方法可以深入研究JSON以获得我需要的或者我以错误的方式接近它？
附加信息： 自发布我原来的问题，我想出了这个（基于东西，我在不同的网站上看到的）：
package JsonRead;
import java.io.File;
import java.io.IOException;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
public class JacksonTreeModel {
public static void main(String[] args) {
try{
ObjectMapper mapper = new ObjectMapper();
JsonNode root = mapper.readTree(new File("JsonRead/json.json"));
JsonNode vaultsNode = root.path("response").path("vault");
/*if(vaultsNode.isArray()){
for(JsonNode node : vaultsNode){
String name = node.path("name").asText();
System.out.println("Array Name: " + name);
}
}*/
for(JsonNode node : vaultsNode){
String name = node.path("name").asText();
String bytesUsed = node.path("sizeFromStorage").asText();
System.out.println("Name: " + name + ", Bytes Used: " + bytesUsed);
}
} catch(IOException e){
System.out.println("IO Exception " + e);
}
}
}
它适用于我想要什么，但有没有更好的方式来做这个？
请问，谢谢你的回复。我会研究你的建议。