Java tutorial
package com.squareup.okhttp.internal.http; import com.squareup.okhttp.Protocol; import com.squareup.okhttp.Response; import java.io.IOException; import java.net.ProtocolException; /** An HTTP response status line like "HTTP/1.1 200 OK". */ public final class StatusLine { /** Numeric status code, 307: Temporary Redirect. */ public static final int HTTP_TEMP_REDIRECT = 307; public static final int HTTP_PERM_REDIRECT = 308; public static final int HTTP_CONTINUE = 100; public final Protocol protocol; public final int code; public final String message; public StatusLine(Protocol protocol, int code, String message) { this.protocol = protocol; this.code = code; this.message = message; } public static StatusLine get(Response response) { return new StatusLine(response.protocol(), response.code(), response.message()); } public static StatusLine parse(String statusLine) throws IOException { // H T T P / 1 . 1 2 0 0 T e m p o r a r y R e d i r e c t // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 // Parse protocol like "HTTP/1.1" followed by a space. int codeStart; Protocol protocol; if (statusLine.startsWith("HTTP/1.")) { if (statusLine.length() < 9 || statusLine.charAt(8) != ' ') { throw new ProtocolException("Unexpected status line: " + statusLine); } int httpMinorVersion = statusLine.charAt(7) - '0'; codeStart = 9; if (httpMinorVersion == 0) { protocol = Protocol.HTTP_1_0; } else if (httpMinorVersion == 1) { protocol = Protocol.HTTP_1_1; } else { throw new ProtocolException("Unexpected status line: " + statusLine); } } else if (statusLine.startsWith("ICY ")) { // Shoutcast uses ICY instead of "HTTP/1.0". protocol = Protocol.HTTP_1_0; codeStart = 4; } else { throw new ProtocolException("Unexpected status line: " + statusLine); } // Parse response code like "200". Always 3 digits. if (statusLine.length() < codeStart + 3) { throw new ProtocolException("Unexpected status line: " + statusLine); } int code; try { code = Integer.parseInt(statusLine.substring(codeStart, codeStart + 3)); } catch (NumberFormatException e) { throw new ProtocolException("Unexpected status line: " + statusLine); } // Parse an optional response message like "OK" or "Not Modified". If it // exists, it is separated from the response code by a space. String message = ""; if (statusLine.length() > codeStart + 3) { if (statusLine.charAt(codeStart + 3) != ' ') { throw new ProtocolException("Unexpected status line: " + statusLine); } message = statusLine.substring(codeStart + 4); } return new StatusLine(protocol, code, message); } @Override public String toString() { StringBuilder result = new StringBuilder(); result.append(protocol == Protocol.HTTP_1_0 ? "HTTP/1.0" : "HTTP/1.1"); result.append(' ').append(code); if (message != null) { result.append(' ').append(message); } return result.toString(); } }