How do I load a resource and use its contents as a string in Spring

Question

How can I load a Spring resource contents and use it to set a bean property or pass it as an argument constructor?

The resource contains free text.

Answer 1

<bean id="contents" class="org.apache.commons.io.IOUtils" factory-method="toString">
    <constructor-arg value="classpath:path/to/resource.txt" type="java.io.InputStream" />
</bean>

This solution requires Apache Commons IO.

Another solution, suggested by @Parvez, without Apache Commons IO dependency is

<bean id="contents" class="java.lang.String">
    <constructor-arg>
        <bean class="org.springframework.util.FileCopyUtils" factory-method="copyToByteArray">
            <constructor-arg value="classpath:path/to/resource.txt" type="java.io.InputStream" />
        </bean>     
    </constructor-arg>
</bean>

Answer 2

daoway answer was very helpful, and following Adrian remark I am adding a configuration snippet similar to daoway's code

<bean id="contents" class="org.springframework.core.io.ClassPathResource">
    <constructor-arg value="path/to/resource.txt"/>
</bean>

From your component

    @Autowired
    private Resource contents;

    @PostConstruct
    public void load(){
        try {
            final InputStream inputStream = contents.getInputStream();
                //use the stream 
            BufferedReader br = new BufferedReader(new InputStreamReader(inputStream ,1024);
            StringBuilder stringBuilder = new StringBuilder();
            String line;
            while ((line = br.readLine()) != null) {
                stringBuilder.append(line).append('\n');
            }
            br.close();
     }catch (IOException e) {
            LOGGER.error(message);
     }
  }

Answer 3

In one line try this to read test.xml:

String msg = StreamUtils.copyToString( new ClassPathResource("test.xml").getInputStream(), Charset.defaultCharset()  );

Answer 4

This is one way of doing it without using any external library.. default provided by spring.. environment.properties file contains key value pairs...reference each value with ${key}

here in my example, I am keeping database props

<bean id="propertyConfigurer"
    class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">
        <list value-type="org.springframework.core.io.Resource">
            <value>classpath:environment.properties</value>

        </list>
    </property>
</bean>
<bean id="mySQLdataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">
    <property name="driverClassName" value="${JDBC.driver}" />
    <property name="url" value="${JDBC.URL}" />
    <property name="username" value="${JDBC.username}" />
    <property name="password" value="${JDBC.password}" />
</bean>

Answer 5

Just read it :

    try {
        Resource resource = new ClassPathResource(fileLocationInClasspath);
        BufferedReader br = new BufferedReader(new InputStreamReader(resource.getInputStream()),1024);
        StringBuilder stringBuilder = new StringBuilder();
        String line;
        while ((line = br.readLine()) != null) {
            stringBuilder.append(line).append('\n');
        }
        br.close();
        return stringBuilder.toString();
    } catch (Exception e) {
        LOGGER.error(e);
    }