com.netflix.iep.http.ServerSentEvent.java Source code

Introduction

Here is the source code for com.netflix.iep.http.ServerSentEvent.java

Source

/*
 * Copyright 2015 Netflix, Inc.
 *
 * 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 com.netflix.iep.http;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;

import java.io.UnsupportedEncodingException;
import java.nio.charset.Charset;

/**
 * Server sent event message.
 */
public final class ServerSentEvent {

    private static ByteBuf toByteBuf(String s) {
        try {
            return Unpooled.wrappedBuffer(s.getBytes("UTF-8"));
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }

    /**
     * Parse a server sent event line from the ByteBuf.
     */
    public static ServerSentEvent parse(ByteBuf buf) {
        return parse(buf.toString(Charset.forName("UTF-8")));
    }

    /**
     * Parse a server sent event line from the String.
     */
    public static ServerSentEvent parse(String line) {
        //http://www.w3.org/TR/eventsource/#event-stream-interpretation

        // The line is empty (a blank line)
        //   Dispatch the event, as defined below.
        // If the line starts with a U+003A COLON character (:)
        //   Ignore the line.
        if (line == null || "".equals(line) || line.startsWith(":")) {
            return null;
        }

        int pos = line.indexOf(':');
        if (pos != -1) {
            // The line contains a U+003A COLON character (:)
            //   Collect the characters on the line before the first U+003A COLON character (:), and
            //   let field be that string.
            String field = line.substring(0, pos);

            //   Collect the characters on the line after the first U+003A COLON character (:), and
            //   let value be that string. If value starts with a U+0020 SPACE character, remove it
            //   from value.
            ++pos;
            String value = "";
            if (pos < line.length()) {
                if (line.charAt(pos) == ' ') {
                    ++pos;
                }
                value = (pos < line.length()) ? line.substring(pos) : "";
            }
            return new ServerSentEvent(field, value);
        } else {
            // Otherwise, the string is not empty but does not contain a U+003A COLON character (:)
            //   Process the field using the steps described below, using the whole line as the field
            //   name, and the empty string as the field value.
            return new ServerSentEvent(line, "");
        }
    }

    private final String field;
    private final String value;

    /**
     * Create a new instance of a server sent event. Neither field or value can be null.
     */
    public ServerSentEvent(String field, String value) {
        if (field == null) {
            throw new NullPointerException("field");
        }

        if (value == null) {
            throw new NullPointerException("value");
        }

        this.field = field;
        this.value = value;
    }

    /** Return the field for the event. */
    public String field() {
        return field;
    }

    /** Return the value for the event. */
    public String value() {
        return value;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null || !(obj instanceof ServerSentEvent))
            return false;
        ServerSentEvent other = (ServerSentEvent) obj;
        return field.equals(other.field) && value.equals(other.value);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int hc = prime;
        hc = prime * hc + field.hashCode();
        hc = prime * hc + value.hashCode();
        return hc;

    }

    @Override
    public String toString() {
        return String.format("%s: %s\n\n", field, value);
    }
}