java - 创建文件..xml中定义的名称为“..”的bean时出错

你能帮我吗？ 1.我的道

package user.dao.impl;

import java.sql.ResultSet;
import java.sql.SQLException;

import javax.sql.DataSource;
import org.springframework.jdbc.core.JdbcTemplate;
import org.springframework.jdbc.core.RowCallbackHandler;
import org.springframework.jdbc.datasource.DataSourceTransactionManager;
import user.domain.DboBean;

public class DboDao {
    private DataSourceTransactionManager transactionManager;
    private JdbcTemplate jdbcTemplate;

    public DboDao() {
        // TODO Auto-generated constructor stub
        super();
        DataSource datatSource = transactionManager.getDataSource();
        jdbcTemplate = new JdbcTemplate(datatSource);
    }

//Spring setter injector used
public void setTransactionManager(DataSourceTransactionManager transactionManager){
    this.transactionManager = transactionManager;
}


public DboBean read() {//String dboId
    // TODO Auto-generated method stub
    String sql = "SELECT ins_ID, ins_name FROM da_tracking "
            + "WHERE ins_ID = 3";
    final Object[] params = new Object[] {};//dboId

    //Creating object being queried
    final DboBean dboBean = new DboBean();
    //Process query Results
    jdbcTemplate.query(sql, params, new RowCallbackHandler(){
        public void processRow(ResultSet rs) throws SQLException{
            dboBean.setDboId(rs.getString("dboId"));
        }

    });
    return dboBean;//returns queried objects
}
}

2.我的豆子：

 package user.domain;

 public class DboBean {

    private String dboId;
    private String dboDevName;

    public DboBean(){
        this.setDboId(dboId);
        this.setDboDevName(dboDevName);
    }

    public String getDboId() {
        return dboId;
    }

    public void setDboId(String dboId) {
        this.dboId = dboId;
    }

    public String getDboDevName() {
        return dboDevName;
    }

    public void setDboDevName(String dboDevName) {
        this.dboDevName = dboDevName;
    }
 }

我的春天：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:lang="http://www.springframework.org/schema/lang"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd
http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang-3.1.xsd">

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
    destroy-method="close">
    <property name="driverClassName" value="net.sourceforge.jtds.jdbc.Driver" />
    <property name="url"
        value="jdbc:jtds:sqlserver://localhost:1433;databaseName=XYDB" />
    <property name="username" value="user" />
    <property name="password" value="xyz" />
</bean>

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="objDbo" class="user.dao.impl.DboDao">
    <property name="transactionManager" ref="transactionManager" />
</bean>

</beans>

而我的Junit：

package user.dao.JUnitTest;

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;

import org.apache.log4j.xml.DOMConfigurator;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.FileSystemXmlApplicationContext;
import java.lang.Object;

import user.dao.impl.DboDao;
import user.domain.DboBean;


public class JUnitDaoTest extends TestCase {
private static final String OID = "dboId";
private static final String DDN = "dboDevName";
protected static ApplicationContext appContext;
private DboDao objDao;

public JUnitDaoTest(String arg) {
    super(arg);
}

public static Test suite(){
    TestSuite suite = new TestSuite();
    suite.addTest(new JUnitDaoTest("testDboDAO"));
    return suite;
}

public void setUp() throws Exception{
    init();
    objDao =  (DboDao) getBean("objDao");
}

public static void main(String[] args){
    junit.textui.TestRunner.run(suite());
}
//@Override
public synchronized void init(){
    if (appContext == null){
        try{
            String path = System.getProperty("user.dir");
            String slash = System.getProperty("file.separator");

            String configDir = path + slash + "config" + slash;
            DOMConfigurator.configure(configDir +  "log4j.xml");

            appContext = new FileSystemXmlApplicationContext(new String[] {configDir + "appContext.xml"});
        }catch(Exception e){
            System.err.println(e.getMessage());
        }
    }
}

protected Object getBean(String beanName){
    return appContext.getBean(beanName);
}


public void testDboDAO(){
    DboBean record = new DboBean();
    record.setDboId(OID);//setDboId(dboId);
    record.setDboDevName(DDN);



    DboBean bean = objDao.read();
    assertEquals(DDN, bean.getDboDevName());
    System.out.println("User selected [" + bean.getDboId() + ", " + bean.getDboDevName() +
            "]");

    //objDao.delete(dboId);
    //bean = objDao.read(dboId);
    //assertEquals(null, bean.getDboDevName());
    //System.out.println("User is deleted [" + bean.getDboId() + ", " + bean.getDboDevName() +
        //  "]");

}

}

我收到此错误：
创建文件[... \ config \ appContext.xml]中定义的名称为'objDbo'的bean时出错：实例化bean失败；嵌套的异常是org.springframework.beans.BeanInstantiationException：无法实例化bean类[user.dao.impl.DboDao]：构造方法抛出了异常；嵌套异常是java.l

你有主意吗？
斑点

最佳答案

stacktrace将解释确切的问题，它将出现在您切断的stacktrace的“嵌套异常为java.l ...”部分之后的任何地方。阅读整个错误消息。

如果我猜测一下，您的DboDao类在构造函数中有一个空指针异常，因为您引用的是尚未设置的字段transactionManager。

我建议编写此DboDao类的单元测试-根本不涉及Spring-测试在调用new DboDao()时会发生什么。

同样，您可能会发现让DAO类仅扩展Spring实用程序类JdbcDaoSupport会很方便。