Indexing SOLRJ-6.0.0：插入一个bean对象，该bean对象关联的bean对象列表给出空指针异常

员工Bean类：

public class Employee2 {

    private String id;
    private String name;
    private String designation;
    private double salary;
    private double totalExperience;
//    private Address2 address2;
    private Collection<Technology2> technologies2;
    private String content_type = "employee2";

    public Employee2() {
        super();
    }

    public Employee2(String id, String name, String designation, double salary, double totalExperience,
            Collection<Technology2> technologies2) {
        super();
        this.id = id;
        this.name = name;
        this.designation = designation;
        this.salary = salary;
        this.totalExperience = totalExperience;
//        this.address2 = address2;
        this.technologies2 = technologies2;
    }

    /**
     * @return the id
     */
    public String getId() {
        return id;
    }

    /**
     * @param id the id to set
     */
    @Field (value = "id")
    public void setId(String id) {
        this.id = id;
    }

    /**
     * @return the name
     */
    public String getName() {
        return name;
    }

    /**
     * @param name the name to set
     */
    @Field (value = "name")
    public void setName(String name) {
        this.name = name;
    }

    /**
     * @return the designation
     */
    public String getDesignation() {
        return designation;
    }

    /**
     * @param designation the designation to set
     */
    @Field (value = "designation_s")
    public void setDesignation(String designation) {
        this.designation = designation;
    }

    /**
     * @return the salary
     */
    public double getSalary() {
        return salary;
    }

    /**
     * @param salary the salary to set
     */
    @Field (value = "salary_d")
    public void setSalary(double salary) {
        this.salary = salary;
    }

    /**
     * @return the totalExperience
     */
    public double getTotalExperience() {
        return totalExperience;
    }

    /**
     * @param totalExperience the totalExperience to set
     */
    @Field (value = "totalExperience_d")
    public void setTotalExperience(double totalExperience) {
        this.totalExperience = totalExperience;
    }

//    /**
//     * @return the address2
//     */
//    public Address2 getAddress() {
//        return address2;
//    }
//
//    /**
//     * @param address2 the address2 to set
//     */
//    @Field (child = true)
//    public void setAddress(Address2 address2) {
//        this.address2 = address2;
//    }

    /**
     * @return the technologies2
     */
    public Collection<Technology2> getTechnologies2() {
        return technologies2;
    }

    /**
     * @param technologies2 the technologies2 to set
     */
    @Field (child = true)
    public void setTechnologies2(Collection<Technology2> technologies2) {
        this.technologies2 = technologies2;
    }

    /**
     * @return the content_type
     */
    public String getContent_type() {
        return content_type;
    }

    /**
     * @param content_type the content_type to set
     */
    @Field(value="content_type_t")
    public void setContent_type(String content_type) {
        this.content_type = content_type;
    }

    /* (non-Javadoc)
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "Employee2 [id=" + id + ", name=" + name + ", designation=" + designation + ", salary=" + salary +
                ", totalExperience=" + totalExperience + ", technologies2=" + this.getTechnologies(technologies2) +
                ", content_type=" + content_type + "]";
    }

    private String getTechnologies(Collection<Technology2> technologies2) {
        String strTechnologies = "[";
        for(Technology2 technology: technologies2) {
            strTechnologies = strTechnologies+technology.toString();
        }
        return strTechnologies+"]";
    }

}

public class Technology2 {

    private String id;
    private String name;
    private int experience;
    private boolean certified;
    private String content_type = "technology2";


    public Technology2() {
        super();
    }

    public Technology2(String id, String name, int experience, boolean certified) {
        super();
        this.id = id;
        this.name = name;
        this.experience = experience;
        this.certified = certified;
    }

    /**
     * @return the id
     */
    public String getId() {
        return id;
    }
    /**
     * @param id the id to set
     */
    @Field(value="id")
    public void setId(String id) {
        this.id = id;
    }
    /**
     * @return the name
     */
    public String getName() {
        return name;
    }
    /**
     * @param name the name to set
     */
    @Field(value="name")
    public void setName(String name) {
        this.name = name;
    }
    /**
     * @return the experience
     */
    public int getExperience() {
        return experience;
    }
    /**
     * @param experience the experience to set
     */
    @Field(value="experience_i")
    public void setExperience(int experience) {
        this.experience = experience;
    }
    /**
     * @return the certified
     */
    public boolean getCertified() {
        return certified;
    }
    /**
     * @param certified the certified to set
     */
    @Field(value="certified_b")
    public void setCertified(boolean certified) {
        this.certified = certified;
    }
    /**
     * @return the content_type
     */
    public String getContent_type() {
        return content_type;
    }
    /**
     * @param content_type the content_type to set
     */
    @Field(value="content_type_t")
    public void setContent_type(String content_type) {
        this.content_type = content_type;
    }
    /* (non-Javadoc)
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "Technology2 [id=" + id + ", name=" + name + ", experience=" + experience + ", certified=" + certified +
                ", content_type=" + content_type + "]";
    }

若EmployeeBean有一个嵌套的地址Bean，那个么Bean插入方法就可以正常工作，但在我们的例子中，EmployeeBean有一个嵌套的技术Bean集合，它在下面一行引起异常

UpdateResponse response=solrClient.addBean（bean）

插入方法：

public <T> boolean insert (T bean) {
        try {
            UpdateResponse response = solrClient.addBean(bean);
            System.out.println("insert bean ElapsedTime: " + response.getElapsedTime());
            solrClient.commit();
            return true;
        } catch (IOException | SolrServerException e) {
            e.printStackTrace();
        }
        return false;
    }

公共布尔插入（T bean）{
试一试{
UpdateResponse response=solrClient.addBean（bean）；
System.out.println（“插入bean ElapsedTime:+response.getElapsedTime（））；
solrClient.commit（）；
返回true；
}捕获（IOException | SolrServer异常）{
e、 printStackTrace（）；
}
返回false；
}

这里它返回空指针异常，下面是Employee2的toString值

雇员2[id=EE130S，姓名=Vulrp，名称=NjLtK， 工资=127334.59626719051，总经验=49.989444163266164， 技术2=[Technology2[id=0TE130S，name=uyIOFlh，experience=21， 认证=正确，内容类型=技术2]技术2[id=1TE130S， 姓名=FmZJjak，经验=43，认证=false， content_type=technology2]technology2[id=2TE130S，name=ddJbOXg， 经验=11，认证=错误，内容类型=技术2]技术2 [id=3TE130S，name=rIxumUe，experience=5，certified=true， 内容类型=技术2]]，内容类型=员工2]

它导致以下异常：

java.lang.NullPointerException
    at org.apache.solr.client.solrj.beans.DocumentObjectBinder$DocField.storeType(DocumentObjectBinder.java:243)
    at org.apache.solr.client.solrj.beans.DocumentObjectBinder$DocField.<init>(DocumentObjectBinder.java:183)
    at org.apache.solr.client.solrj.beans.DocumentObjectBinder.collectInfo(DocumentObjectBinder.java:144)
    at org.apache.solr.client.solrj.beans.DocumentObjectBinder.getDocFields(DocumentObjectBinder.java:123)
    at org.apache.solr.client.solrj.beans.DocumentObjectBinder.toSolrInputDocument(DocumentObjectBinder.java:76)
    at org.apache.solr.client.solrj.SolrClient.addBean(SolrClient.java:277)
    at org.apache.solr.client.solrj.SolrClient.addBean(SolrClient.java:259)
    at com.opteamix.buildpal.poc.SampleSolrDAO.insert(SampleSolrDAO.java:62)
    at com.opteamix.buildpal.poc.SampleSolrDAOTest.testEmployees2Insert(SampleSolrDAOTest.java:94)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at junit.framework.TestCase.runTest(TestCase.java:168)
    at junit.framework.TestCase.runBare(TestCase.java:134)
    at junit.framework.TestResult$1.protect(TestResult.java:110)
    at junit.framework.TestResult.runProtected(TestResult.java:128)
    at junit.framework.TestResult.run(TestResult.java:113)
    at junit.framework.TestCase.run(TestCase.java:124)
    at junit.framework.TestSuite.runTest(TestSuite.java:243)
    at junit.framework.TestSuite.run(TestSuite.java:238)
    at org.junit.internal.runners.JUnit38ClassRunner.run(JUnit38ClassRunner.java:83)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

java.lang.NullPointerException
位于org.apache.solr.client.solrj.beans.DocumentObjectBinder$DocField.storeType（DocumentObjectBinder.java:243）
位于org.apache.solr.client.solrj.beans.DocumentObjectBinder$DocField。（DocumentObjectBinder.java:183）
位于org.apache.solr.client.solrj.beans.DocumentObjectBinder.collectInfo（DocumentObjectBinder.java:144）
位于org.apache.solr.client.solrj.beans.DocumentObjectBinder.getDocFields（DocumentObjectBinder.java:123）
位于org.apache.solr.client.solrj.beans.DocumentObjectBinder.toSolrInputDocument（DocumentObjectBinder.java:76）
位于org.apache.solr.client.solrj.SolrClient.addBean（SolrClient.java:277）
位于org.apache.solr.client.solrj.SolrClient.addBean（SolrClient.java:259）
位于com.opteamix.buildpal.poc.SampleSolrDAO.insert（SampleSolrDAO.java:62）
位于com.opteamix.buildpal.poc.SampleSolrDAOTest.testEmployees2Insert（SampleSolrDAOTest.java:94）
在sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）处
位于sun.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）
在sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）中
位于java.lang.reflect.Method.invoke（Method.java:498）
位于junit.framework.TestCase.runTest（TestCase.java:168）
位于junit.framework.TestCase.runBare（TestCase.java:134）
位于junit.framework.TestResult$1.protect（TestResult.java:110）
位于junit.framework.TestResult.runProtected（TestResult.java:128）
运行（TestResult.java:113）
运行（TestCase.java:124）
位于junit.framework.TestSuite.runTest（TestSuite.java:243）
运行（TestSuite.java:238）
位于org.junit.internal.runners.JUnit38ClassRunner.run（JUnit38ClassRunner.java:83）
位于org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run（JUnit4TestReference.java:86）
位于org.eclipse.jdt.internal.junit.runner.TestExecution.run（TestExecution.java:38）
位于org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests（RemoteTestRunner.java:459）
位于org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests（RemoteTestRunner.java:675）
位于org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run（RemoteTestRunner.java:382）
位于org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main（RemoteTestRunner.java:192）

插入一个与bean列表相关联的bean对象，现在正按预期工作。

最后，在查看了solrj6.0.0源代码之后，我找到了解决它的方法。实际上solrj6.0.0中有一个bug。即: 如果我们在Employee2 bean中给出@Field注释at set方法，如下所示：

/**
     * @param technologies2 the technologies2 to set
     */
    @Field (child = true)
    public void setTechnologies2(Collection<Technology2> technologies2) {
        this.technologies2 = technologies2;
    }

正如我们在setter处注释@Field（child=true），因此在本例中，字段为null，这导致storeType（）方法出现null指针异常

因此，到目前为止，我在字段级别而不是setter上注释@Field annotation：

 @Field (child = true)
    private Collection<Technology2> technologies2;

@字段（child=true）
私人收藏技术2；

所以现在插入这样的bean是成功的，在检索时，我得到了如下预期结果：

雇员2[id=E3，姓名=KzWhg，职务=aTDiu， 工资=190374.70126209356，总经验=2.0293696897450584， 技术2=[Technology2[id=0T3，name=nxTdufv，experience=46， 认证=错误，内容类型=技术2]技术2[id=1T3， 姓名=waSMXpf，经验=26，认证=false， 内容\u type=technology2]technology2[id=2T3，name=jqNbZZr， 经验=30，认证=true，内容类型=technology2]technology2 [id=3T3，name=VnidjyI，experience=21，certified=true， 内容\类型=技术2]技术2[id=4T3，名称=ulGnHFm， 经验=33，认证=错误，内容类型=技术2]技术2 [id=5T3，姓名=cpUfgrY，经验=21，认证=false， 内容类型=技术2]]，内容类型=员工2]员工2[id=E4， 姓名=xeKOY，职务=WfPSm，工资=169700.538692728， 总体经验=22.047282596410284，技术2=[技术2 [id=0T4，name=rleygcW，experience=30，certified=true， 内容\类型=技术2]技术2[id=1T4，名称=yxjHrxV， 经验=27，认证=错误，内容类型=技术2]技术2 [id=2T4，姓名=czjHAEE，经验=31，认证=false， 内容\u type=technology2]technology2[id=3T4，name=RDhoIJw， 经验=22，认证=错误，内容类型=技术2]技术2 [id=4T4，name=UkbldDN，experience=19，certified=false， 内容类型=技术2]]，

private void storeType() {
      if (field != null) {
        type = field.getType();
      } else {
        Class[] params = setter.getParameterTypes();
        if (params.length != 1) {
          throw new BindingException("Invalid setter method. Must have one and only one parameter");
        }
        type = params[0];
      }

      if (type == Collection.class || type == List.class || type == ArrayList.class) {
        isList = true;
        if (annotation.child()) {
          populateChild(field.getGenericType());
        } else {
          type = Object.class;
        }
      } else if (type == byte[].class) {
        //no op
      } else if (type.isArray()) {
        isArray = true;
        if (annotation.child()) {
          populateChild(type.getComponentType());
        } else {
          type = type.getComponentType();
        }
      } else if (type == Map.class || type == HashMap.class) { //corresponding to the support for dynamicFields
        if (annotation.child()) throw new BindingException("Map should is not a valid type for a child document");
        isContainedInMap = true;
        //assigned a default type
        type = Object.class;
        if (field != null) {
          if (field.getGenericType() instanceof ParameterizedType) {
            //check what are the generic values
            ParameterizedType parameterizedType = (ParameterizedType) field.getGenericType();
            Type[] types = parameterizedType.getActualTypeArguments();
            if (types != null && types.length == 2 && types[0] == String.class) {
              //the key should always be String
              //Raw and primitive types
              if (types[1] instanceof Class) {
                //the value could be multivalued then it is a List, Collection, ArrayList
                if (types[1] == Collection.class || types[1] == List.class || types[1] == ArrayList.class) {
                  type = Object.class;
                  isList = true;
                } else {
                  //else assume it is a primitive and put in the source type itself
                  type = (Class) types[1];
                }
              } else if (types[1] instanceof ParameterizedType) { //Of all the Parameterized types, only List is supported
                Type rawType = ((ParameterizedType) types[1]).getRawType();
                if (rawType == Collection.class || rawType == List.class || rawType == ArrayList.class) {
                  type = Object.class;
                  isList = true;
                }
              } else if (types[1] instanceof GenericArrayType) { //Array types
                type = (Class) ((GenericArrayType) types[1]).getGenericComponentType();
                isArray = true;
              } else { //Throw an Exception if types are not known
                throw new BindingException("Allowed type for values of mapping a dynamicField are : " +
                    "Object, Object[] and List");
              }
            }
          }
        }
      } else {
        if (annotation.child()) {
          populateChild(type);
        }
      }
    }

 @Field (child = true)
    private Collection<Technology2> technologies2;