使用杰克逊解析Json文件

Question

{
   "TestSuite":{
      "TestSuiteInfo":{
         "-description":"parse"
      },
      "TestCase":[
         {
            "TestCaseData":{
               "-sequence":"sequential",
               "-testNumber":"2",
               "-testCaseFile":"testcase\\Web\\Ab.xml"
            }
         },
         {
            "TestCaseData":{
               "-sequence":"sequential",
               "-testNumber":"3",
               "-testCaseFile":"testcase\\Web\\BC.xml"
            }
         }
      ]
   }
}

我的Pojos是:

public class TestSuite {    

    private TestSuiteInfo testSuiteInfo;
    private TestCase listOfTestCases;

    public TestSuiteInfo getTestSuiteInfo() {   
        return testSuiteInfo;
    }

    public void setTestSuiteInfo(TestSuiteInfo testSuiteInfo) {
        this.testSuiteInfo = testSuiteInfo;
    }

    public TestCase getListOfTestCases() {
        return listOfTestCases;
    }

    public void setListOfTestCases(TestCase listOfTestCases) {
        this.listOfTestCases = listOfTestCases;
    }
}


public class TestSuiteInfo {

    private String description;

    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
}


import java.util.Iterator;
import java.util.List;

public class TestCase {

    private List<TestCaseData> testCaseData;

    public List<TestCaseData> getTestCaseData() {
        return testCaseData;
    }

    public void setTestCaseData(List<TestCaseData> testCaseData) {
        this.testCaseData = testCaseData;
    }
}


public class TestCaseData {

    private String sequence;
    private int testNumber;
    private String testCaseFile;

    public String getSequence() {   
        return sequence;
    }

    public void setSequence(String sequence) {
        this.sequence = sequence;
    }

    public int getTestNumber() {
        return testNumber;
    }

    public void setTestNumber(int testNumber) {
        this.testNumber = testNumber;
    }

    public String getTestCaseFile() {
        return testCaseFile;
    }

    public void setTestCaseFile(String testCaseFile) {
        this.testCaseFile = testCaseFile;
    }
}

我之前没有使用过Jackson,如果有人能帮助我解析文件并获取对象,我将非常感激.我试图从过去两天解析这个,但没有取得任何成功

Answer 1

通常用Jackson库解析JSON,你会使用这样的ObjectMapper类:

public static void main(final String[] args) {
    final String json = "some JSON string";
    final ObjectMapper mapper = new ObjectMapper();
    final TestSuite readValue = mapper.readValue(json, TestSuite.class);
    //Then some code that uses the readValue.
    //Keep in mind that the mapper.readValue() method does throw some exceptions
    //So you'll need to handle those too.    
}

但是,我写了一个快速测试类来检查你的JSON的解析并遇到了一些问题.

基本上,JSON的设计和域的设计不匹配.因此,您可以更改JSON,也可以更改域对象.

更改JSON以适应域

1. 其中包含" - "的属性名称不会在jackson中很好地解析,因此需要删除它们.
2. 在每个对象之前拥有类名称将无济于事.杰克逊希望这些属性属性,因此类名称将需要删除或替换属性名称.
3. 必须提供属性名称,因为它们在域对象中,以便jackson解析它们.你不能只说这是一个对象,然后开始一个列表,列表必须有一个属性名称/

在我调整了JSON中的这些东西后,我让它用提供的域对象进行解析.我最终得到的JSON看起来像这样:

{
   "testSuiteInfo":{
      "description":"parse"
   },
   "listOfTestCases":{
      "testCaseData":[
         {
            "sequence":"sequential",
            "testNumber":"2",
            "testCaseFile":"testcase\\Web\\Ab.xml"
         },
         {
            "sequence":"sequential",
            "testNumber":"3",
            "testCaseFile":"testcase\\Web\\BC.xml"
         }
      ]
   }
}

这是我的测试方法,它解析上面的篡改JSON(请忽略所有转义字符)

public static void main(final String[] args) {
    final String json = "{\"testSuiteInfo\":{\"description\":\"parse\"}," +
            "\"listOfTestCases\":{" +
            "\"testCaseData\":[" +
            "{\"sequence\":\"sequential\",\"testNumber\":\"2\",\"testCaseFile\":\"testcase\\\\Web\\\\Ab.xml\"}," +
            "{\"sequence\":\"sequential\",\"testNumber\":\"3\",\"testCaseFile\":\"testcase\\\\Web\\\\BC.xml\"}" +
            "]" +
            "}" +
            "}";

    final ObjectMapper mapper = new ObjectMapper();

    try {
        final TestSuite readValue = mapper.readValue(json, TestSuite.class);
        System.out.println(readValue.getListOfTestCases()); //just a test to see if the object is built
    }
    catch (final Exception e) {
        e.printStackTrace();
    }
}

更改域以适合JSON

首先,主要问题是将类名称作为属性标识符.这使得以常规方式使用此JSON非常困难.我必须添加几个包装类来绕过JSON中的类名.

• 我添加了一个OverallWrapper具有TestSuite属性的类,以满足JSON中的TestSuite类名称.

• 我还添加了一个TestCaseDataWrapper类来满足JSON列表中的TestCaseData类名.

• 我一起删除了TestCase类,因为它刚刚成为其他类之一的属性.

• 然后,为了使属性名称与对象匹配,我使用了@JsonProperty注释.

以下是修改后的类,以及工作和解析JSON的终极解析器测试方法.(再次,请原谅JSON字符串中的所有转义字符)

import org.codehaus.jackson.annotate.JsonProperty;         

public class OverallWrapper {                              

    private TestSuite testSuite;                           

    @JsonProperty("TestSuite")                             
    public TestSuite getTestSuite() {                      
        return this.testSuite;                             
    }                                                      

    public void setTestSuite(final TestSuite testSuite) {  
        this.testSuite = testSuite;                        
    }                                                      
}



import java.util.List;                                                                                                                                  
import org.codehaus.jackson.annotate.JsonProperty;                              

public class TestSuite {                                                        

    private TestSuiteInfo testSuiteInfo;                                        

    private List<TestCaseDataWrapper> testCaseData;                             

    @JsonProperty("TestCase")                                                   
    public List<TestCaseDataWrapper> getTestCaseData() {                        
        return this.testCaseData;                                               
    }                                                                           

    public void setTestCaseData(final List<TestCaseDataWrapper> testCaseData) { 
        this.testCaseData = testCaseData;                                       
    }                                                                           

    @JsonProperty("TestSuiteInfo")                                              
    public TestSuiteInfo getTestSuiteInfo() {                                   
        return this.testSuiteInfo;                                              
    }                                                                           

    public void setTestSuiteInfo(final TestSuiteInfo testSuiteInfo) {           
        this.testSuiteInfo = testSuiteInfo;                                     
    }                                                                                                                                                   
}          



import org.codehaus.jackson.annotate.JsonProperty;          

public class TestSuiteInfo {                                

    private String description;                             

    @JsonProperty("-description")                           
    public String getDescription() {                        
        return this.description;                            
    }                                                       
    public void setDescription(final String description) {  
        this.description = description;                     
    }                                                       
}                                                                                                                                



import org.codehaus.jackson.annotate.JsonProperty;                  

public class TestCaseDataWrapper {                                  

    @JsonProperty("TestCaseData")                                   
    private TestCaseData testcaseData;                              

    public TestCaseData getTestcaseData() {                         
        return this.testcaseData;                                   
    }                                                               

    public void setTestcaseData(final TestCaseData testcaseData) {  
        this.testcaseData = testcaseData;                           
    }                                                               
}       



import org.codehaus.jackson.annotate.JsonProperty;             

public class TestCaseData {                                    

    private String sequence;                                   
    private int testNumber;                                    
    private String testCaseFile;                               

    @JsonProperty("-sequence")                                 
    public String getSequence() {                              
        return this.sequence;                                  
    }                                                          

    public void setSequence(final String sequence) {           
        this.sequence = sequence;                              
    }                                                          

    @JsonProperty("-testNumber")                               
    public int getTestNumber() {                               
        return this.testNumber;                                
    }                                                          

    public void setTestNumber(final int testNumber) {          
        this.testNumber = testNumber;                          
    }                                                          

    @JsonProperty("-testCaseFile")                             
    public String getTestCaseFile() {                          
        return this.testCaseFile;                              
    }                                                          

    public void setTestCaseFile(final String testCaseFile) {   
        this.testCaseFile = testCaseFile;                      
    }                                                          
}                                                              



public static void main(final String[] args) {

    final String json = "{\"TestSuite\":{\"TestSuiteInfo\":{\"-description\":\"parse\"},\"TestCase\":[" +
            "{\"TestCaseData\":{\"-sequence\":\"sequential\",\"-testNumber\":\"2\",\"-testCaseFile\":\"testcase\\\\Web\\\\Ab.xml\"}}," +
            "{\"TestCaseData\":{\"-sequence\":\"sequential\",\"-testNumber\":\"3\",\"-testCaseFile\":\"testcase\\\\Web\\\\BC.xml\"}}" +
            "]}}";

    final ObjectMapper mapper = new ObjectMapper();

    try {
        final OverallWrapper readValue = mapper.readValue(json, OverallWrapper.class);

        System.out.println(readValue.getTestSuite());
    }
    catch (final Exception e) {
        e.printStackTrace();
    }
}

加起来

最终的问题是该域名不与JSON结合.

我个人更喜欢将JSON更改为与域名结合,因为域名在设计中似乎有意义,并且需要较少的自定义和强制.

但是,我确实接受你可能没有那个选择,因此重新设计域名.