问题
All,
I have the following JSON output/string (its a response from JIRA API):
{
"expand": "names,schema",
"startAt": 0,
"maxResults": 50,
"total": 1,
"issues": [
{
"expand": "operations,versionedRepresentations,editmeta,changelog,transitions,renderedFields",
"id": "18200",
"self": "https://localhost/rest/api/2/issue/18200",
"key": "LS-1111",
"fields": {
"issuetype": {
"self": "https://localhost/rest/api/2/issuetype/3",
"id": "3",
"description": "A task that needs to be done.",
"iconUrl": "https://localhost/secure/viewavatar?size=xsmall&avatarId=10318&avatarType=issuetype",
"name": "Task",
"subtask": false,
"avatarId": 10318
},
"timespent": 21600,
"aggregatetimespent": 25200,
"resolution": null,
"customfield_11201": null,
"project": {
"self": "https://localhost/rest/api/2/project/10100",
"id": "10100",
"key": "PROJKEY",
"name": "ProjectABCD",
"avatarUrls": {
"48x48": "https://localhost/secure/projectavatar?pid=10100&avatarId=10600",
"24x24": "https://localhost/secure/projectavatar?size=small&pid=10100&avatarId=10600",
"16x16": "https://localhost/secure/projectavatar?size=xsmall&pid=10100&avatarId=10600",
"32x32": "https://localhost/secure/projectavatar?size=medium&pid=10100&avatarId=10600"
}
},
"issuelinks": [
{
"id": "16202",
"self": "https://localhost/rest/api/2/issueLink/16202",
"type": {
"id": "10003",
"name": "Relates",
"inward": "relates to",
"outward": "relates to",
"self": "https://localhost/rest/api/2/issueLinkType/10003"
}
}
]
}
}
]
}
I am using GSON for traversing through the elements and getting the values. I have written POJO classes following the "Nested Objects" example at
http://www.javacreed.com/gson-deserialiser-example/
I am able to get the element values till 2nd level. Eg:
I am able to get the value of response.expand, response.issues.get(0).expand and other values till this level.
How can I get the value of response.issues.get(0).fields.issuetype.id?
How should I construct my deserializer and POJO class. Please assist. Thanks.
回答1:
Try this -
AvatarUrls.java
public class AvatarUrls {
private String _48x48;
private String _24x24;
private String _16x16;
private String _32x32;
public String get_48x48() {
return _48x48;
}
public void set_48x48(String _48x48) {
this._48x48 = _48x48;
}
public String get_24x24() {
return _24x24;
}
public void set_24x24(String _24x24) {
this._24x24 = _24x24;
}
public String get_16x16() {
return _16x16;
}
public void set_16x16(String _16x16) {
this._16x16 = _16x16;
}
public String get_32x32() {
return _32x32;
}
public void set_32x32(String _32x32) {
this._32x32 = _32x32;
}
@Override
public String toString() {
return "AvatarUrls [_48x48=" + _48x48 + ", _24x24=" + _24x24
+ ", _16x16=" + _16x16 + ", _32x32=" + _32x32 + "]";
}
}
Example.java
import java.util.ArrayList;
import java.util.List;
public class Example {
private String expand;
private Integer startAt;
private Integer maxResults;
private Integer total;
private List<Issue> issues = new ArrayList<Issue>();
public String getExpand() {
return expand;
}
public void setExpand(String expand) {
this.expand = expand;
}
public Integer getStartAt() {
return startAt;
}
public void setStartAt(Integer startAt) {
this.startAt = startAt;
}
public Integer getMaxResults() {
return maxResults;
}
public void setMaxResults(Integer maxResults) {
this.maxResults = maxResults;
}
public Integer getTotal() {
return total;
}
public void setTotal(Integer total) {
this.total = total;
}
public List<Issue> getIssues() {
return issues;
}
public void setIssues(List<Issue> issues) {
this.issues = issues;
}
@Override
public String toString() {
return "Example [expand=" + expand + ", startAt=" + startAt
+ ", maxResults=" + maxResults + ", total=" + total
+ ", issues=" + issues + "]";
}
}
Fields.java
import java.util.ArrayList;
import java.util.List;
public class Fields {
private Issuetype issuetype;
private Integer timespent;
private Integer aggregatetimespent;
private Object resolution;
private Object customfield11201;
private Project project;
private List<Issuelink> issuelinks = new ArrayList<Issuelink>();
public Issuetype getIssuetype() {
return issuetype;
}
public void setIssuetype(Issuetype issuetype) {
this.issuetype = issuetype;
}
public Integer getTimespent() {
return timespent;
}
public void setTimespent(Integer timespent) {
this.timespent = timespent;
}
public Integer getAggregatetimespent() {
return aggregatetimespent;
}
public void setAggregatetimespent(Integer aggregatetimespent) {
this.aggregatetimespent = aggregatetimespent;
}
public Object getResolution() {
return resolution;
}
public void setResolution(Object resolution) {
this.resolution = resolution;
}
public Object getCustomfield11201() {
return customfield11201;
}
public void setCustomfield11201(Object customfield11201) {
this.customfield11201 = customfield11201;
}
public Project getProject() {
return project;
}
public void setProject(Project project) {
this.project = project;
}
public List<Issuelink> getIssuelinks() {
return issuelinks;
}
public void setIssuelinks(List<Issuelink> issuelinks) {
this.issuelinks = issuelinks;
}
@Override
public String toString() {
return "Fields [issuetype=" + issuetype + ", timespent=" + timespent
+ ", aggregatetimespent=" + aggregatetimespent
+ ", resolution=" + resolution + ", customfield11201="
+ customfield11201 + ", project=" + project + ", issuelinks="
+ issuelinks + "]";
}
}
Issue.java
public class Issue {
private String expand;
private String id;
private String self;
private String key;
private Fields fields;
public String getExpand() {
return expand;
}
public void setExpand(String expand) {
this.expand = expand;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getSelf() {
return self;
}
public void setSelf(String self) {
this.self = self;
}
public String getKey() {
return key;
}
public void setKey(String key) {
this.key = key;
}
public Fields getFields() {
return fields;
}
public void setFields(Fields fields) {
this.fields = fields;
}
@Override
public String toString() {
return "Issue [expand=" + expand + ", id=" + id + ", self=" + self
+ ", key=" + key + ", fields=" + fields + "]";
}
}
Issuelink.java
public class Issuelink {
private String id;
private String self;
private Type type;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getSelf() {
return self;
}
public void setSelf(String self) {
this.self = self;
}
public Type getType() {
return type;
}
public void setType(Type type) {
this.type = type;
}
@Override
public String toString() {
return "Issuelink [id=" + id + ", self=" + self + ", type=" + type
+ "]";
}
}
Issuetype.java
public class Issuetype {
private String self;
private String id;
private String description;
private String iconUrl;
private String name;
private Boolean subtask;
private Integer avatarId;
public String getSelf() {
return self;
}
public void setSelf(String self) {
this.self = self;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public String getIconUrl() {
return iconUrl;
}
public void setIconUrl(String iconUrl) {
this.iconUrl = iconUrl;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Boolean getSubtask() {
return subtask;
}
public void setSubtask(Boolean subtask) {
this.subtask = subtask;
}
public Integer getAvatarId() {
return avatarId;
}
public void setAvatarId(Integer avatarId) {
this.avatarId = avatarId;
}
@Override
public String toString() {
return "Issuetype [self=" + self + ", id=" + id + ", description="
+ description + ", iconUrl=" + iconUrl + ", name=" + name
+ ", subtask=" + subtask + ", avatarId=" + avatarId + "]";
}
}
Project.java
public class Project {
private String self;
private String id;
private String key;
private String name;
private AvatarUrls avatarUrls;
public String getSelf() {
return self;
}
public void setSelf(String self) {
this.self = self;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getKey() {
return key;
}
public void setKey(String key) {
this.key = key;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public AvatarUrls getAvatarUrls() {
return avatarUrls;
}
public void setAvatarUrls(AvatarUrls avatarUrls) {
this.avatarUrls = avatarUrls;
}
@Override
public String toString() {
return "Project [self=" + self + ", id=" + id + ", key=" + key
+ ", name=" + name + ", avatarUrls=" + avatarUrls + "]";
}
}
Type.java
public class Type {
private String id;
private String name;
private String inward;
private String outward;
private String self;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getInward() {
return inward;
}
public void setInward(String inward) {
this.inward = inward;
}
public String getOutward() {
return outward;
}
public void setOutward(String outward) {
this.outward = outward;
}
public String getSelf() {
return self;
}
public void setSelf(String self) {
this.self = self;
}
@Override
public String toString() {
return "Type [id=" + id + ", name=" + name + ", inward=" + inward
+ ", outward=" + outward + ", self=" + self + "]";
}
}
Now you can test it as -
Main.java
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.testgson.beans.Example;
public class Main {
private static Gson gson;
static {
gson = new GsonBuilder().create();
}
/**
* @param args
*/
public static void main(String[] args) {
String j = "{\"expand\":\"names,schema\",\"startAt\":0,\"maxResults\":50,\"total\":1,\"issues\":[{\"expand\":\"operations,versionedRepresentations,editmeta,changelog,transitions,renderedFields\",\"id\":\"18200\",\"self\":\"https://localhost/rest/api/2/issue/18200\",\"key\":\"LS-1111\",\"fields\":{\"issuetype\":{\"self\":\"https://localhost/rest/api/2/issuetype/3\",\"id\":\"3\",\"description\":\"A task that needs to be done.\",\"iconUrl\":\"https://localhost/secure/viewavatar?size=xsmall&avatarId=10318&avatarType=issuetype\",\"name\":\"Task\",\"subtask\":false,\"avatarId\":10318},\"timespent\":21600,\"aggregatetimespent\":25200,\"resolution\":null,\"customfield_11201\":null,\"project\":{\"self\":\"https://localhost/rest/api/2/project/10100\",\"id\":\"10100\",\"key\":\"PROJKEY\",\"name\":\"ProjectABCD\",\"avatarUrls\":{\"48x48\":\"https://localhost/secure/projectavatar?pid=10100&avatarId=10600\",\"24x24\":\"https://localhost/secure/projectavatar?size=small&pid=10100&avatarId=10600\",\"16x16\":\"https://localhost/secure/projectavatar?size=xsmall&pid=10100&avatarId=10600\",\"32x32\":\"https://localhost/secure/projectavatar?size=medium&pid=10100&avatarId=10600\"}},\"issuelinks\":[{\"id\":\"16202\",\"self\":\"https://localhost/rest/api/2/issueLink/16202\",\"type\":{\"id\":\"10003\",\"name\":\"Relates\",\"inward\":\"relates to\",\"outward\":\"relates to\",\"self\":\"https://localhost/rest/api/2/issueLinkType/10003\"}}]}}]}";
Example r = gson.fromJson(j, Example.class);
System.out.println(r);
// This is how traversal can be done
List<Issue> issues = r.getIssues();
for(Issue i: issues) {
System.out.println("Expand - " + i.getExpand());
System.out.println("Id - " + i.getId());
System.out.println("Self - " + i.getSelf());
System.out.println("Key - " + i.getKey());
System.out.println("Fields - " + i.getFields());
}
}
}
Result is -
Example [expand=names,schema, startAt=0, maxResults=50, total=1, issues=[Issue [expand=operations,versionedRepresentations,editmeta,changelog,transitions,renderedFields, id=18200, self=https://localhost/rest/api/2/issue/18200, key=LS-1111, fields=Fields [issuetype=Issuetype [self=https://localhost/rest/api/2/issuetype/3, id=3, description=A task that needs to be done., iconUrl=https://localhost/secure/viewavatar?size=xsmall&avatarId=10318&avatarType=issuetype, name=Task, subtask=false, avatarId=10318], timespent=21600, aggregatetimespent=25200, resolution=null, customfield11201=null, project=Project [self=https://localhost/rest/api/2/project/10100, id=10100, key=PROJKEY, name=ProjectABCD, avatarUrls=AvatarUrls [_48x48=null, _24x24=null, _16x16=null, _32x32=null]], issuelinks=[Issuelink [id=16202, self=https://localhost/rest/api/2/issueLink/16202, type=Type [id=10003, name=Relates, inward=relates to, outward=relates to, self=https://localhost/rest/api/2/issueLinkType/10003]]]]]]]
来源：https://stackoverflow.com/questions/33007600/deserializing-nested-json-string-using-gson