How to properly send an HTTP message to the client

Question

I\'m working on a RESTful web service in Java. I need a good way to send error messages to the client if something\'s wrong.

According to the Javadoc, HttpServlet

Answer 1

In Spring powered web application, running on Tomcat I use following bean:

import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

import org.springframework.beans.factory.InitializingBean;

public class SystemPropertiesInitializingBean implements InitializingBean {

    private Map<String, String> systemProperties;

    @Override
    public void afterPropertiesSet() throws Exception {
        if (null == systemProperties || systemProperties.isEmpty()) {
            return;
        }

        final Set<Entry<String, String>> entrySet = systemProperties.entrySet();
        for (final Entry<String, String> entry : entrySet) {

            final String key = entry.getKey();
            final String value = entry.getValue();

            System.setProperty(key, value);
        }

    }

    public void setSystemProperties(final Map<String, String> systemProperties) {
        this.systemProperties = systemProperties;
    }

}

And in applicationContext.xml:

<bean class="....SystemPropertiesInitializingBean">
    <property name="systemProperties">
        <map>
            <entry key="org.apache.coyote.USE_CUSTOM_STATUS_MSG_IN_HEADER" value="true"/>
        </map>
    </property>
</bean>