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我试图将我的 Spring MVC 表单控制器更改为注释控制器，但我遇到了一些问题。

当我在 glassfish 服务器上部署我的应用程序时，当我想访问 hello.htm 时出现以下错误

Avertissement: StandardWrapperValve[dispatcher]: PWC1406: Servlet.service() for servlet dispatcher threw exception
java.lang.NullPointerException
at hibernateTest.web.InventoryController.getClient(InventoryController.java:38)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:436)
at org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:424)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:770)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
at     com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
at java.lang.Thread.run(Thread.java:722)

这是我的 web.xml ：

<?xml version="1.0" encoding="UTF-8"?> 

<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
     xmlns="http://java.sun.com/xml/ns/javaee" 
     xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
     id="WebApp_ID" 
     version="2.5">

<context-param> 
    <param-name>contextConfigLocation</param-name>
    <param-value>
        /WEB-INF/dispatcher-servlet.xml, /WEB-INF/applicationContext.xml
    </param-value>
</context-param> 

<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<servlet>
    <servlet-name>dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>dispatcher</servlet-name>
    <url-pattern>*.htm</url-pattern>
</servlet-mapping>

<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>

调度程序-servlet.xml：

<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
  xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
  http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"
  default-autowire="byName">

<context:component-scan base-package="hibernateTest.web" />

<context:annotation-config/>

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/>

<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver" 
      p:prefix="/WEB-INF/jsp/" 
      p:suffix=".jsp" />

<bean id="propertyConfigurer" 
      class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <list>
            <value>classpath:jdbc.properties</value>
        </list>
    </property>
</bean>

库存控制器：

import com.mysql.jdbc.Constants;
import hibernateTest.service.ProductManager;
import java.util.HashMap;
import java.util.Map;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;

@Controller
public class InventoryController { 

protected final Log logger = LogFactory.getLog(getClass()); 

private ProductManager productManager; 

public void setProductManager(ProductManager productManager) {
    this.productManager = productManager;
} 

@RequestMapping(value="/hello.htm",method = RequestMethod.GET)
public String getClient(ModelMap model) {

    logger.info("returning hello view"); 
    model.addAttribute("products", this.productManager.getProducts());
    return "hello"; 
}
 }

简单产品经理：

import hibernateTest.domain.Product; 
import hibernateTest.repository.ProductDao;
 import java.util.List; 
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.stereotype.Service;

@Service()
public class SimpleProductManager implements ProductManager { 

protected final Log logger = LogFactory.getLog(getClass()); 

private ProductDao productDao; 

public void increasePrice(int percentage) {

    List<Product> products = productDao.getProductList();

    if (products != null) {

        for (Product product : products) {

            double newPrice = product.getPrice().doubleValue() * (100 + percentage)/100;
            product.setPrice(newPrice);
            productDao.saveProduct(product);

        }

    }

} 

public void createProduct(String description, Double price) {

    Product prod = new Product();

    prod.setDescription(description);
    prod.setPrice(price);

    logger.info("Class SimpleProductManager - Description set to " + description);
    logger.info("Class SimpleProductManager - Price set to " + price);

    productDao.insertProduct(prod);

}

public List<Product> getProducts() {

    return productDao.getProductList();

} 

public void setProductDao(ProductDao productDao) {

    this.productDao = productDao;

} 
}

JdbcProductDao ：

import hibernateTest.domain.Product;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List; 

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.jdbc.core.simple.ParameterizedRowMapper;
import org.springframework.jdbc.core.support.JdbcDaoSupport;
import org.springframework.stereotype.Repository;

@Repository
public class JdbcProductDao extends JdbcDaoSupport implements ProductDao { 

/** Logger for this class and subclasses */
protected final Log logger = LogFactory.getLog(getClass()); 

public List<Product> getProductList() {

    logger.info("Getting products!");

    List<Product> products = getJdbcTemplate().query(
            "select id, description, price from products", 
            new ProductMapper());

    return products;

} 

public void saveProduct(Product prod) {

    logger.info("Saving product: " + prod.getDescription());

    int count = getJdbcTemplate().update(
            "update products set description = ?, price = ? where id = ?",
            new Object[]{prod.getDescription(), prod.getPrice(), prod.getId()});

    logger.info("Rows affected: " + count);

}    

public void insertProduct(Product prod) {

    logger.info("Inserting product: " + prod.getDescription());

    getJdbcTemplate().update(
            "insert into products (description, price) values (?, ?)",
            new Object[]{prod.getDescription(), prod.getPrice()});

    logger.info("Inserting product " + prod.getDescription() + "ok");

}
private static class ProductMapper implements ParameterizedRowMapper<Product> { 

    public Product mapRow(ResultSet rs, int rowNum) throws SQLException {

        Product prod = new Product();

        prod.setId(rs.getInt("id"));
        prod.setDescription(rs.getString("description"));
        prod.setPrice(new Double(rs.getDouble("price")));

        return prod;

    } 

} 

}

感谢您的帮助！

4

2 回答 2

1

您需要通过自动装配告诉控制器 ProductManager 是什么。

@autowired 私有 ProductManager 产品经理；

于 2012-11-15T14:22:23.760 回答
0

bean 应该在 spring 上下文配置 XML 中声明。

 <bean id="productDao" class="JdbcProductDao"/>

并注意

<context:component-scan base-package="hibernateTest.web" />

确保包包含所有包含的注释配置。

于 2012-11-15T21:18:59.097 回答