org.springframework.batch.admin.web.JsonWrapper.java Source code

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Here is the source code for org.springframework.batch.admin.web.JsonWrapper.java

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/*
 * Copyright 2009-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.springframework.batch.admin.web;

import java.util.Map;

import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.MappingJsonFactory;

import org.springframework.context.expression.MapAccessor;
import org.springframework.expression.spel.standard.SpelExpressionParser;
import org.springframework.expression.spel.support.StandardEvaluationContext;

public class JsonWrapper {

    private final SpelExpressionParser parser;

    private final StandardEvaluationContext context;

    private final Map<String, Object> target;

    private final String content;

    @SuppressWarnings("unchecked")
    public JsonWrapper(String content) throws Exception {
        this.content = content;
        try {
            target = new MappingJsonFactory().createJsonParser(content.replace("\\", "/")).readValueAs(Map.class);
        } catch (JsonParseException e) {
            throw new JsonMappingException("Cannot create wrapper for:\n" + content, e);
        }
        context = new StandardEvaluationContext();
        context.addPropertyAccessor(new MapAccessor());
        parser = new SpelExpressionParser();
    }

    public Map<String, Object> getMap() {
        return target;
    }

    public Object get(String expression) throws Exception {
        return get(expression, Object.class);
    }

    public <T> T get(String expression, Class<T> type) throws Exception {
        return parser.parseExpression(expression).getValue(context, target, type);
    }

    @Override
    public String toString() {
        return content;
    }

}