java - Spring propertyConfigurer 不工作

Question

我遇到了以下问题，propertyConfigurer 的注入(inject)属性似乎不起作用。

我得到的错误是...

Caused by: java.lang.NumberFormatException: For input string: "${db.maxactive}"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48)
    at java.lang.Integer.parseInt(Integer.java:449)
    at java.lang.Integer.valueOf(Integer.java:554)
    at org.springframework.util.NumberUtils.parseNumber(NumberUtils.java:155)
    at org.springframework.beans.propertyeditors.CustomNumberEditor.setAsText(CustomNumberEditor.java:115)
    at org.springframework.beans.TypeConverterDelegate.doConvertTextValue(TypeConverterDelegate.java:434)
    at org.springframework.beans.TypeConverterDelegate.doConvertValue(TypeConverterDelegate.java:406)
    at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:163)
    at org.springframework.beans.BeanWrapperImpl.convertIfNecessary(BeanWrapperImpl.java:470)

从堆栈跟踪中，它试图将值“${db.maxactive}”注入(inject)到 dbcp 驱动程序中。如果我打开日志记录，我可以看到以下内容(这是我不注入(inject)该属性时的堆栈跟踪)...

[INFO] Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@19bd03e: startup date [Thu Jun 27 08:58:08 BST 2013]; root of context hierarchy
[INFO] Loading XML bean definitions from class path resource [conf/spring/applicationContext-StandAlone.xml]
[INFO] Loading XML bean definitions from class path resource [conf/spring/applicationContext-monitoring.xml]
[INFO] Loading XML bean definitions from class path resource [conf/spring/dataAccessContext-local.xml]
[INFO] Loading XML bean definitions from class path resource [conf/spring/applicationContext-jdbc.xml]
[INFO] Loading XML bean definitions from class path resource [conf/spring/applicationContext-beans.xml]
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/C:/Users/porterj/.m2/repository/org/slf4j/slf4j-jdk14/1.6.1/slf4j-jdk14-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/C:/Users/porterj/.m2/repository/org/slf4j/slf4j-nop/1.6.1/slf4j-nop-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.

**** 在加载 jdbc.properties 之前，此处抛出异常。 [INFO] 从类路径资源 [jdbc.properties] 加载属性文件

这让我觉得 propertyConfigurer 是在它尝试注入(inject)值之后加载的，因此它注入(inject)的是参数名称，而不是参数值。

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

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

  <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="${db.driver}"/>
    <property name="url" value="${db.url}"/>
    <property name="username" value="${db.username}"/>
    <property name="password" value="${db.password}"/>
    <property name="maxActive" value="${db.maxactive}"/>
  </bean>

然后我的 jdbc.properties 文件...

db.driver=com.ibm.db2.jcc.DB2Driver
db.url=jdbc:db2://dbserver:51000/db
db.username=dm
db.password=pass
db.maxactive=20

Java 类...

ApplicationContext context = new ClassPathXmlApplicationContext("classpath:/applicationContext-StandAlone.xml");

有人可以给我一些建议吗，这是因为我是通过独立应用程序执行此操作的吗？我已经在 Web 应用程序中多次执行此操作，并且 propertyConfigurer 工作正常。

注:Spring 3.1.2.RELEASE

        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
        <groupId>org.springframework</groupId>
        <artifactId>spring-tx</artifactId>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jms</artifactId>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>

Answer 1

我以前在我开发的应用程序中见过一次；我发现问题与mybatis有关，并且SqlSessionFactoryBean有问题。我没有深入挖掘，但如果您想进行更多研究，请从这个 link 开始- 即使您不使用 mybatis，也可能是类似的东西。

我可以看到我的 bean 正在被实例化，并且在从文件加载属性之前设置了它们的属性。

我没有使用 Spring PropertyPlaceholderConfigurer，而是不得不使用 spring 的“util:properties”机制来加载属性——一旦我转向这个，它就开始工作了。试试下面的代码 - 可能对你有用......

<?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:util="http://www.springframework.org/schema/util"
       xsi:schemaLocation="http://www.springframework.org/schema/beans 
       http://www.springframework.org/schema/beans/spring-beans.xsd 
       http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.0.xsd">

  <util:properties id="dataSourceProps" location="classpath:jdbc.properties"/>

  <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
    <property name="driverClassName" value="#{dataSourceProps['db.driver']}" />
    <property name="url" value="#{dataSourceProps['db.url']}" />
    <property name="username" value="#{dataSourceProps['db.username']}" />
    <property name="password" value="#{dataSourceProps['db.password']}" />
    <property name="maxActive" value="#{dataSourceProps['db.maxactive']}" />
  </bean>

  ....

</beans>