如何在REST服务中验证传入的JSON数据？

Question

休息服务需要根据json模式验证所有传入的json数据.json模式是公共可访问的,可以通过http请求检索.

我正在使用jackson -framwork来编组java和json之间的编组和解组.到目前为止,我找不到任何使用jackson来验证模式数据的可能性.

我还尝试了JsonTools框架,它显然提出了这样的验证功能.但不幸的是,我无法让验证工作.为什么JsonTool架构验证不起作用？

我该怎么做这样的验证？

Answer 1

我搜索了对传入的json数据进行RESTful服务验证的最佳实践.我的建议是使用a MessageBodyReader在readFrom方法中执行验证.下面是一个消息体阅读器示例,为简单起见,它是非通用的.

我也很想找到做json数据验证的最佳框架.因为我使用jackson框架(版本1.8.5)在json和java之间进行编组和解组,所以如果这个框架提供json数据验证功能会很好.不幸的是我找不到与杰克逊这样做的可能性.最后,我使用了https://github.com上提供的json-schema-validator.我使用的版本是2.1.7

import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;

import javax.servlet.ServletContext;
import javax.ws.rs.Consumes;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyReader;
import javax.ws.rs.ext.Provider;

import org.codehaus.jackson.map.ObjectMapper;

import at.fhj.ase.dao.data.Address;
import at.fhj.ase.xmlvalidation.msbreader.MessageBodyReaderValidationException;

import com.fasterxml.jackson.databind.JsonNode;
import com.github.fge.jackson.JsonLoader;
import com.github.fge.jsonschema.exceptions.ProcessingException;
import com.github.fge.jsonschema.main.JsonSchemaFactory;
import com.github.fge.jsonschema.main.JsonValidator;
import com.github.fge.jsonschema.report.ProcessingReport;

@Provider
@Consumes(MediaType.APPLICATION_JSON)
public class AddressJsonValidationReader implements MessageBodyReader<Address> {

    private final String jsonSchemaFileAsString;

    public AddressJsonValidationReader(@Context ServletContext servletContext) {
        this.jsonSchemaFileAsString = servletContext
                .getRealPath("/json/Address.json");
    }

    @Override
    public boolean isReadable(Class<?> type, Type genericType,
            Annotation[] annotations, MediaType mediaType) {
        if (type == Address.class) {
            return true;
        }
        return false;
    }

    @Override
    public Address readFrom(Class<Address> type, Type genericType,
            Annotation[] annotations, MediaType mediaType,
            MultivaluedMap<String, String> httpHeaders, InputStream entityStream)
            throws IOException, WebApplicationException {

        final String jsonData = getStringFromInputStream(entityStream);
        System.out.println(jsonData);

        InputStream isSchema = new FileInputStream(jsonSchemaFileAsString);
        String jsonSchema = getStringFromInputStream(isSchema);

        /*
         * Perform JSON data validation against schema
         */
        validateJsonData(jsonSchema, jsonData);

        /*
         * Convert stream to data entity
         */
        ObjectMapper m = new ObjectMapper();
        Address addr = m.readValue(stringToStream(jsonData), Address.class);

        return addr;
    }

    /**
     * Validate the given JSON data against the given JSON schema
     * 
     * @param jsonSchema
     *            as String
     * @param jsonData
     *            as String
     * @throws MessageBodyReaderValidationException
     *             in case of an error during validation process
     */
    private void validateJsonData(final String jsonSchema, final String jsonData)
            throws MessageBodyReaderValidationException {
        try {
            final JsonNode d = JsonLoader.fromString(jsonData);
            final JsonNode s = JsonLoader.fromString(jsonSchema);

            final JsonSchemaFactory factory = JsonSchemaFactory.byDefault();
            JsonValidator v = factory.getValidator();

            ProcessingReport report = v.validate(s, d);
            System.out.println(report);
            if (!report.toString().contains("success")) {
                throw new MessageBodyReaderValidationException(
                        report.toString());
            }

        } catch (IOException e) {
            throw new MessageBodyReaderValidationException(
                    "Failed to validate json data", e);
        } catch (ProcessingException e) {
            throw new MessageBodyReaderValidationException(
                    "Failed to validate json data", e);
        }
    }

    /**
     * Taken from <a href=
     * "http://www.mkyong.com/java/how-to-convert-inputstream-to-string-in-java/"
     * >www.mkyong.com</a>
     * 
     * @param is
     *            {@link InputStream}
     * @return Stream content as String
     */
    private String getStringFromInputStream(InputStream is) {
        BufferedReader br = null;
        StringBuilder sb = new StringBuilder();

        String line;
        try {

            br = new BufferedReader(new InputStreamReader(is));
            while ((line = br.readLine()) != null) {
                sb.append(line);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

        return sb.toString();
    }

    private InputStream stringToStream(final String str) throws UnsupportedEncodingException {
        return new ByteArrayInputStream(str.getBytes("UTF-8"));
    }

}

Answer 2

import com.github.fge.jsonschema.core.report.ProcessingReport;
import com.github.fge.jsonschema.main.JsonSchema;
import com.github.fge.jsonschema.main.JsonSchemaFactory;
import com.github.fge.jackson.JsonLoader;
import com.fasterxml.jackson.databind.JsonNode;

public class ValidationJSON {
    public static void main(String[] arr){
       String jsonData = "{\"name\": \"prem\"}";
       String jsonSchema = ""; //Schema we can generate online using http://jsonschema.net/
       final JsonNode data = JsonLoader.fromString(jsonData);
       final JsonNode schema = JsonLoader.fromString(jsonSchema);

       final JsonSchemaFactory factory = JsonSchemaFactory.byDefault();
       JsonValidator validator = factory.getValidator();

       ProcessingReport report = validator.validate(schema, data);
       System.out.println(report.isSuccess());
    }

}