[How to Fix]Spring 3.0 could not find acceptable representation

When using Spring 3.0.5 MVC development, JSON interface data development, using JSONObject.fromobObject (Object) to return JSON data. Problems with “org. Springframework. Web. HttpMediaTypeNotAcceptableException: Could not find acceptable representation” error.

Solution 1:
The @responseBody method’s return type is changed from JSONObject to Object.
Modify SpringMVC-servlet.xml to add MessageConverters

<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
<!-- Object->json -->
<property name="messageConverters"> 
<list> 
<bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" /> 
</list> 
</property> 
</bean>

JacksonJar package support is required: jackson-core-lgpl-1.2.1.jar and jackson-core-lgpl-1.2.1.jar.

Solution 2:
The @responseBody method returns a String instead of a JSONObject, and returns JSONObject.fromobObject (Object).toString();
At this time, if there is Chinese, there will be garbled code, the solution is as follows:

 <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
	    <!-- Object->json -->
	    <!-- <property name="messageConverters">  
		    <list>  
		         <bean class="org.springframework.http.converter.json.MappingJacksonHttpMessageConverter" />  
		    </list>   
	    </property> -->
	    <!-- default is ISO you should set utf-8 -->
	    <property name="messageConverters">  
        <list>  
            <bean  
                class="org.springframework.http.converter.StringHttpMessageConverter">  
                <property name="supportedMediaTypes">  
                    <list>  
                        <bean class="org.springframework.http.MediaType">  
                            <constructor-arg index="0" value="text" />  
                            <constructor-arg index="1" value="plain" />  
                            <constructor-arg index="2" value="UTF-8" />  
                        </bean>  
                    </list>  
                </property>  
            </bean>  
        </list>  
    </property>  
    </bean>

Solution 3:
The return type is JSONObject. Write your own Converter.

package javacommon.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.nio.charset.Charset;

import org.springframework.http.HttpInputMessage;
import org.springframework.http.HttpOutputMessage;
import org.springframework.http.MediaType;
import org.springframework.http.converter.AbstractHttpMessageConverter;
import org.springframework.http.converter.HttpMessageNotReadableException;
import org.springframework.http.converter.HttpMessageNotWritableException;

public class JaksonConverter extends AbstractHttpMessageConverter<Object> {
	public static final Charset DEFAULT_CHARSET = Charset.forName("UTF-8");
	
	public JaksonConverter() {
		super(new MediaType("application", "json", DEFAULT_CHARSET));
	}
	
	@Override
	protected boolean supports(Class<?> clazz) {
		// TODO Auto-generated method stub
		return false;
	}

	@Override
	protected Object readInternal(Class<?extends Object> clazz,
			HttpInputMessage inputMessage) throws IOException,
			HttpMessageNotReadableException {
		logger.info(clazz.getSimpleName());
		InputStream inputStream=inputMessage.getBody();
		StringBuilder stringBuilder = new StringBuilder();
		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
		String line = null; 
		while((line = bufferedReader.readLine()) != null){
			stringBuilder.append(line);
		}
		logger.info(stringBuilder.toString());
		return stringBuilder;
	}

	@Override
	protected void writeInternal(Object t, HttpOutputMessage outputMessage)
			throws IOException, HttpMessageNotWritableException {
		logger.info(t.getClass().getSimpleName());
		
		// HashMap
		// JSONObject
		logger.info(t.toString());
		OutputStream os=outputMessage.getBody();
		 
		os.write(t.toString().getBytes("utf-8")); 
		os.flush();
		
	}

}

Replace the Converter in Scenario 1 with a written one.

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