Question

我在外部.properties文件中设置了一个变量，但是当我尝试调用该值时，它会一直返回null。我们有另一个项目正在导入外部.properties文件，该文件工作正常，但即使使用它作为模型，我也无法弄清楚为什么这个文件不起作用。以下相关文件。

具体来说，返回NULL的是PropertiesUtil.getProperty("property.file.variable");

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">

    <display-name>PROJECT</display-name>

    <servlet>
        <servlet-name>Jersey REST Service</servlet-name>
        <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>com.sun.jersey.config.property.packages</param-name>
            <param-value>com.bar.foo.rest</param-value>
        </init-param>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:applicationContext.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>Jersey REST Service</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>

    <listener>
        <listener-class>com.bar.foo.rest.ListenerClass</listener-class>
    </listener>

</web-app>

的applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:tx="http://www.springframework.org/schema/tx" 
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">

    <tx:annotation-driven />
    <context:annotation-config />
    <mvc:annotation-driven />

    <context:component-scan base-package="com.bar.foo;" />

    <context:property-placeholder location="file:${externalConfiguration}" />

    <bean id="propertyConfigurer" class="com.bar.foo.utils.PropertiesUtil">
        <property name="ignoreResourceNotFound" value="true" />
        <property name="ignoreUnresolvablePlaceholders" value="true" />
        <property name="locations">
            <list>
                <value>classpath:PROJECT.properties</value>
                <value>file:${externalConfiguration}</value>
            </list>
        </property>
    </bean>

    <bean id="configProperties"
        class="org.springframework.beans.factory.config.PropertiesFactoryBean">
        <property name="ignoreResourceNotFound" value="true" />
        <property name="locations">
            <list>
                <value>classpath:PROJECT.properties</value>
                <value>file:${externalConfiguration}</value>
            </list>
        </property>
    </bean>
</beans>

的pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>com.bar</groupId>
        <artifactId>PROJECT</artifactId>
        <version>1.30.1-SNAPSHOT</version>
    </parent>
    <artifactId>PROJECT</artifactId>
    <packaging>war</packaging>

    <properties>
        <org.springframework-version>3.1.0.RELEASE</org.springframework-version>
        <spring.batch.version>3.0.0.RELEASE</spring.batch.version>
    </properties>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <!-- <version>2.3.2</version> -->
                <configuration>
                    <source>1.6</source>
                    <target>1.6</target>
                    <compilerArgument>-Xlint:all</compilerArgument>
                    <showWarnings>true</showWarnings>
                    <showDeprecation>true</showDeprecation>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.codehaus.mojo</groupId>
                <artifactId>exec-maven-plugin</artifactId>
                <version>1.2.1</version>
                <configuration>
                    <mainClass>org.test.int1.Main</mainClass>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-surefire-plugin</artifactId>
                <version>2.16</version>
                <configuration>
                    <argLine>-XX:-UseSplitVerifier</argLine>
                </configuration>
            </plugin>
        </plugins>
    </build>

    <dependencies>

        <!-- This dependency (version unspecified) is needed at runtime by Tomcat. 
            I don't know why but I had to add it manually. -->
        <dependency>
            <groupId>asm</groupId>
            <artifactId>asm</artifactId>
            <version>3.3.1</version>
            <scope>runtime</scope>
        </dependency>

        <dependency>
            <groupId>com.sun.jersey</groupId>
            <artifactId>jersey-bundle</artifactId>
            <version>1.10</version>
        </dependency>

        <dependency>
            <groupId>javax.jdo</groupId>
            <artifactId>jdo2-api</artifactId>
            <version>2.3-eb</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>${org.springframework-version}</version>
            <exclusions>
                <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${org.springframework-version}</version>
            <exclusions>
                <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context-support</artifactId>
            <version>${org.springframework-version}</version>
            <exclusions>
                <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${org.springframework-version}</version>
            <exclusions>
                <!-- Exclude Commons Logging in favor of SLF4j -->
                <exclusion>
                    <groupId>commons-logging</groupId>
                    <artifactId>commons-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${org.springframework-version}</version>
        </dependency>
    </dependencies>
</project>

PropertiesUtil.java

package com.bar.foo.utils;

import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;

public class PropertiesUtil extends PropertyPlaceholderConfigurer {

    private static Map<String, String> propertiesMap = new HashMap<String, String>();
    // Default as in PropertyPlaceholderConfigurer
    private int springSystemPropertiesMode = SYSTEM_PROPERTIES_MODE_FALLBACK;

    /**
     * Workaround: PropertyPlaceholderConfigurer.systemPropertiesMode is not
     * directly accessible
     */
    @Override
    public void setSystemPropertiesMode(int systemPropertiesMode) {
        super.setSystemPropertiesMode(systemPropertiesMode);
        springSystemPropertiesMode = systemPropertiesMode;
    }

    @Override
    protected void processProperties(ConfigurableListableBeanFactory beanFactory, Properties props) {
        super.processProperties(beanFactory, props);

        for (Object key : props.keySet()) {
            String keyStr = key.toString();
            String valueStr = resolvePlaceholder(keyStr, props, springSystemPropertiesMode);
            propertiesMap.put(keyStr, valueStr);
        }
    }

    public static String getProperty(String name) {
        return propertiesMap.get(name);
    }
}

Answer 1

找到解决方案。结果我的web.xml设置错了。我已经尝试了正确的语法，但是我的tomcat服务器配置错误导致错误（NoClassDefFoundError: javax.servlet.ServletException），在不同的服务器实例上部署项目似乎已修复。正确的配置如下：

添加到web.xml：

<servlet>
<servlet-name>appServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
</servlet>

属性文件中的值返回null

1 个答案: