Java/Android - 根据 String schema 验证 String JSON

感谢Douglas Crockford和Francis Galiegue编写基于java的json模式处理器！http://json-schema-validator.herokuapp.com/index.jsp 的在线测试仪非常棒！我真的很喜欢有用的错误消息（我只发现了一个它们失败的例子），尽管行和列和/或上下文会更好（现在，你只能在JSON格式错误期间获得行和列信息（由Jackson提供）。最后，我要感谢Michael Droettboom的出色教程（即使他只涵盖了Python，Ruby和C，而明显忽略了所有最好的语言：-））。

对于那些错过它的人（就像我一开始所做的那样），有一些例子 github.com/fge/json-schema-processor-examples。虽然这些示例非常令人印象深刻，但它们并不是最初请求的简单json验证示例（我也在寻找）。简单的例子 github.com/fge/json-schema-validator/blob/master/src/main/java/com/github/fge/jsonschema/examples/Example1.java

Alex上面的代码对我不起作用，但非常有帮助;我的pom正在拉取最新的稳定版本，版本2.0.1，在我的maven pom.xml文件中插入了以下依赖项：

<dependency>
    <groupId>com.github.fge</groupId>
    <artifactId>json-schema-validator</artifactId>
    <version>2.0.1</version>
</dependency>

然后下面的java代码对我来说工作正常：

import java.io.IOException;
import java.util.Iterator;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonNode;
import com.github.fge.jsonschema.exceptions.ProcessingException;
import com.github.fge.jsonschema.main.JsonSchema;
import com.github.fge.jsonschema.main.JsonSchemaFactory;
import com.github.fge.jsonschema.report.ProcessingMessage;
import com.github.fge.jsonschema.report.ProcessingReport;
import com.github.fge.jsonschema.util.JsonLoader;


public class JsonValidationExample  
{

public boolean validate(String jsonData, String jsonSchema) {
    ProcessingReport report = null;
    boolean result = false;
    try {
        System.out.println("Applying schema: @<@<"+jsonSchema+">@>@ to data: #<#<"+jsonData+">#>#");
        JsonNode schemaNode = JsonLoader.fromString(jsonSchema);
        JsonNode data = JsonLoader.fromString(jsonData);         
        JsonSchemaFactory factory = JsonSchemaFactory.byDefault(); 
        JsonSchema schema = factory.getJsonSchema(schemaNode);
        report = schema.validate(data);
    } catch (JsonParseException jpex) {
        System.out.println("Error. Something went wrong trying to parse json data: #<#<"+jsonData+
                ">#># or json schema: @<@<"+jsonSchema+">@>@. Are the double quotes included? "+jpex.getMessage());
        //jpex.printStackTrace();
    } catch (ProcessingException pex) {  
        System.out.println("Error. Something went wrong trying to process json data: #<#<"+jsonData+
                ">#># with json schema: @<@<"+jsonSchema+">@>@ "+pex.getMessage());
        //pex.printStackTrace();
    } catch (IOException e) {
        System.out.println("Error. Something went wrong trying to read json data: #<#<"+jsonData+
                ">#># or json schema: @<@<"+jsonSchema+">@>@");
        //e.printStackTrace();
    }
    if (report != null) {
        Iterator<ProcessingMessage> iter = report.iterator();
        while (iter.hasNext()) {
            ProcessingMessage pm = iter.next();
            System.out.println("Processing Message: "+pm.getMessage());
        }
        result = report.isSuccess();
    }
    System.out.println(" Result=" +result);
    return result;
}

public static void main(String[] args)
{
    System.out.println( "Starting Json Validation." );
    JsonValidationExample app = new JsonValidationExample();
    String jsonData = "\"Redemption\"";
    String jsonSchema = "{ \"type\": \"string\", \"minLength\": 2, \"maxLength\": 11}";
    app.validate(jsonData, jsonSchema);
    jsonData = "Agony";  // Quotes not included
    app.validate(jsonData, jsonSchema);
    jsonData = "42";
    app.validate(jsonData, jsonSchema);
    jsonData = "\"A\"";
    app.validate(jsonData, jsonSchema);
    jsonData = "\"The pity of Bilbo may rule the fate of many.\"";
    app.validate(jsonData, jsonSchema);
}

}

我从上面的代码中得到的结果是：

Starting Json Validation.
Applying schema: @<@<{ "type": "string", "minLength": 2, "maxLength": 11}>@>@ to data: #<#<"Redemption">#>#
 Result=true
Applying schema: @<@<{ "type": "string", "minLength": 2, "maxLength": 11}>@>@ to data: #<#<Agony>#>#
Error. Something went wrong trying to parse json data: #<#<Agony>#># or json schema: @<@<{ "type": "string", "minLength": 2, "maxLength": 11}>@>@. Are the double quotes included?
 Result=false
Applying schema: @<@<{ "type": "string", "minLength": 2, "maxLength": 11}>@>@ to data: #<#<42>#>#
Processing Message: instance type does not match any allowed primitive type
 Result=false
Applying schema: @<@<{ "type": "string", "minLength": 2, "maxLength": 11}>@>@ to data: #<#<"A">#>#
Processing Message: string is too short
 Result=false
Applying schema: @<@<{ "type": "string", "minLength": 2, "maxLength": 11}>@>@ to data: #<#<"The pity of Bilbo may rule the fate of many.">#>#
Processing Message: string is too long
 Result=false

享受！

这基本上就是你链接到的Servlet所做的，所以它可能不是一行，但它仍然是富有表现力的。

useV4和 servlet 上指定的，用于为 和 指定验证选项。useIdDefault to draft v4Use id for addressing

您可以在线查看：http://json-schema-validator.herokuapp.com/

public boolean validate(String jsonData, String jsonSchema, boolean useV4, boolean useId) throws Exception {
   // create the Json nodes for schema and data
   JsonNode schemaNode = JsonLoader.fromString(jsonSchema); // throws JsonProcessingException if error
   JsonNode data = JsonLoader.fromString(jsonData);         // same here

   JsonSchemaFactory factory = JsonSchemaFactories.withOptions(useV4, useId);
   // load the schema and validate
   JsonSchema schema = factory.fromSchema(schemaNode);
   ValidationReport report = schema.validate(data);

   return report.isSuccess();
}