com.huawei.streaming.config.ConfVariable.java Source code

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Here is the source code for com.huawei.streaming.config.ConfVariable.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 com.huawei.streaming.config;

import java.util.Locale;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.common.base.Strings;
import com.huawei.streaming.exception.ErrorCode;
import com.huawei.streaming.exception.StreamingException;

/**
 * ????
 *
 */
public class ConfVariable {
    /**
     * ????
     */
    public static final String CONF_VARIABLE_PREFIX = "${";

    /**
     * ????
     */
    public static final String CONF_VARIABLE_POSTFIX = "}";

    /**
     * ?System???
     */
    public static final String SYSTEM_PREFIX = "system:";

    /**
     * ?CQL??
     */
    public static final String CQLCONF_PREFIX = "conf:";

    private static final Logger LOG = LoggerFactory.getLogger(ConfVariable.class);

    private ConfValueType type = ConfValueType.COMMON;

    private String name;

    /**
     * ?
     */
    private String preStr = "";

    /**
     * ?
     */
    private String postStr = "";

    /**
     * 
     * ?????
     *
     * @param value ?
     */
    public ConfVariable(final String value) {
        name = value;
        if (Strings.isNullOrEmpty(value)) {
            return;
        }

        String newValue = value.trim();
        int startIndex = newValue.indexOf(CONF_VARIABLE_PREFIX);
        int endIndex = newValue.indexOf(CONF_VARIABLE_POSTFIX);
        if (startIndex != -1 && endIndex != -1) {
            preStr = newValue.substring(0, startIndex);
            postStr = newValue.substring(endIndex + 1);

            if (preStr == null) {
                preStr = "";
            }

            if (postStr == null) {
                postStr = "";
            }

            String variableString = newValue.substring(startIndex, endIndex + 1);
            parseVariableConf(variableString);
        }

        //???????
        //????
        if (newValue.startsWith(CONF_VARIABLE_PREFIX) && newValue.endsWith(CONF_VARIABLE_POSTFIX)) {
            parseVariableConf(newValue);
        }
    }

    /**
     * ?
     * ?set
     *
     * @param confVariable ????
     * @param conf ?
     * @param userConf  ?
     * @return ?
     * @throws StreamingException ?
     */
    public static String getValue(ConfVariable confVariable, Map<String, Object> conf, Map<String, String> userConf)
            throws StreamingException {
        String value = null;
        switch (confVariable.type) {
        case SYSTEM:
            value = System.getProperty(confVariable.getName());
            break;
        case CONF:
            value = getConfValue(confVariable.getName(), conf, userConf);
            break;
        default:
            return confVariable.getName();
        }
        return confVariable.getPreStr() + value + confVariable.getPostStr();
    }

    /**
     * ??
     * Get
     * get??????
     *
     * @param confVariable ????
     * @param conf ?
     * @param userConf  ?
     * @return ?
     * @throws StreamingException ?
     */
    public static String getKey(ConfVariable confVariable, Map<String, Object> conf, Map<String, String> userConf)
            throws StreamingException {
        String value = null;
        switch (confVariable.type) {
        case SYSTEM:
            value = System.getProperty(confVariable.getName());
            break;
        default:
            value = getConfValue(confVariable.getName(), conf, userConf);
        }

        return confVariable.getPreStr() + value + confVariable.getPostStr();
    }

    private static String getConfValue(String name, Map<String, Object> conf, Map<String, String> userConf)
            throws StreamingException {
        if (userConf != null && userConf.containsKey(name)) {
            return userConf.get(name);
        }

        if (conf != null && conf.containsKey(name)) {
            return conf.get(name).toString();
        }

        StreamingException exception = new StreamingException(ErrorCode.CONFIG_NOT_FOUND, name);
        LOG.error(exception.getMessage(), exception);
        throw exception;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public ConfValueType getType() {
        return type;
    }

    public void setType(ConfValueType type) {
        this.type = type;
    }

    public String getPreStr() {
        return preStr;
    }

    public String getPostStr() {
        return postStr;
    }

    private void parseVariableConf(String value) {
        //trim???
        String variable = StringUtils
                .removeEnd(StringUtils.removeStart(value, CONF_VARIABLE_PREFIX), CONF_VARIABLE_POSTFIX).trim();
        if (Strings.isNullOrEmpty(variable)) {
            return;
        }

        if (variable.toLowerCase(Locale.US).startsWith(SYSTEM_PREFIX)) {
            parseSystemVariable(variable);
            return;
        }

        if (variable.toLowerCase(Locale.US).startsWith(CQLCONF_PREFIX)) {
            parseConfVariable(variable);
            return;
        }
    }

    private void parseConfVariable(String value) {
        String variable = value.substring(CQLCONF_PREFIX.length()).trim();
        if (!Strings.isNullOrEmpty(variable)) {
            type = ConfValueType.CONF;
            name = variable;
        }
    }

    private void parseSystemVariable(String value) {
        String variable = value.substring(SYSTEM_PREFIX.length()).trim();
        if (!Strings.isNullOrEmpty(variable)) {
            type = ConfValueType.SYSTEM;
            name = variable;
        }
    }

}