net.officefloor.server.http.HttpException Maven / Gradle / Ivy
/*-
* #%L
* HTTP Server
* %%
* Copyright (C) 2005 - 2020 Daniel Sagenschneider
* %%
* 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.
* #L%
*/
package net.officefloor.server.http;
import java.io.PrintWriter;
import java.io.StringWriter;
import net.officefloor.server.stream.StreamBuffer;
import net.officefloor.server.stream.StreamBufferPool;
/**
*
* HTTP {@link Exception}.
*
* This is a {@link RuntimeException} as typically this is handled directly by
* the {@link HttpServerImplementation} to send a {@link HttpResponse}. It is
* typically not for application logic to handle.
*
* @author Daniel Sagenschneider
*/
public class HttpException extends RuntimeException {
/**
* Serial version UID.
*/
private static final long serialVersionUID = 1L;
/**
* {@link HttpHeader} space.
*/
private static byte[] SPACE = " ".getBytes(ServerHttpConnection.HTTP_CHARSET);
/**
* {@link HttpHeader} end of line encoded bytes.
*/
private static byte[] HEADER_EOLN = "\r\n".getBytes(ServerHttpConnection.HTTP_CHARSET);
/**
* {@link HttpHeader} name/value separation.
*/
private static byte[] COLON_SPACE = ": ".getBytes(ServerHttpConnection.HTTP_CHARSET);
/**
* Content-Length {@link HttpHeaderName}.
*/
private static HttpHeaderName CONTENT_LENGTH = new HttpHeaderName("Content-Length");
/**
* No {@link WritableHttpHeader} instances value.
*/
private static final WritableHttpHeader[] NO_HEADERS = new WritableHttpHeader[0];
/**
* {@link HttpStatus}.
*/
private final HttpStatus status;
/**
* Possible {@link WritableHttpHeader} instances for the {@link HttpResponse}.
*/
private final WritableHttpHeader[] headers;
/**
* {@link HttpResponse} entity content.
*/
private final String entity;
/**
* Instantiate.
*
* @param status {@link HttpStatus}.
*/
public HttpException(HttpStatus status) {
super(status.getStatusMessage());
this.status = status;
this.headers = NO_HEADERS;
this.entity = null;
}
/**
* Instantiate.
*
* @param status {@link HttpStatus}.
* @param cause {@link Throwable} cause.
*/
public HttpException(HttpStatus status, Throwable cause) {
super(cause);
this.status = status;
this.headers = NO_HEADERS;
this.entity = null;
}
/**
* Convenience constructor for providing error message.
*
* @param statusCode Status code.
* @param errorMessage Error message.
*/
public HttpException(int statusCode, String errorMessage) {
this(HttpStatus.getHttpStatus(statusCode), errorMessage);
}
/**
* Convenience constructor for providing error message.
*
* @param status {@link HttpStatus}.
* @param errorMessage Error message.
*/
public HttpException(HttpStatus status, String errorMessage) {
super(new ErrorMessageException(errorMessage));
this.status = status;
this.headers = NO_HEADERS;
this.entity = null;
}
/**
* Instantiate.
*
* @param status {@link HttpStatus}.
* @param headers {@link HttpHeader} instances. May be null.
* @param entity Entity for the {@link HttpResponse}. May be null.
*/
public HttpException(HttpStatus status, WritableHttpHeader[] headers, String entity) {
super(status.getStatusMessage());
this.status = status;
this.headers = (headers == null ? NO_HEADERS : headers);
this.entity = entity;
}
/**
* Enable wrapping {@link Throwable} in a {@link HttpException} for
* {@link HttpStatus#INTERNAL_SERVER_ERROR}.
*
* @param cause {@link Throwable} cause.
*/
public HttpException(Throwable cause) {
this(HttpStatus.INTERNAL_SERVER_ERROR, cause);
}
/**
* Obtains the {@link HttpStatus} for the {@link HttpResponse}.
*
* @return {@link HttpStatus} for the {@link HttpResponse}.
*/
public HttpStatus getHttpStatus() {
return this.status;
}
/**
* Obtains the {@link HttpHeader} instances.
*
* @return {@link HttpHeader} instances.
*/
public HttpHeader[] getHttpHeaders() {
return this.headers;
}
/**
* Obtains the entity for the {@link HttpResponse}.
*
* @return Entity for the {@link HttpResponse}.
*/
public String getEntity() {
return this.entity;
}
/**
* Writes the HTTP response for this {@link HttpException}.
*
* @param Buffer type.
* @param version {@link HttpVersion}.
* @param isIncludeStackTrace Whether to include the stack trace.
* @param head Head {@link StreamBuffer} of the linked list of
* {@link StreamBuffer} instances.
* @param bufferPool {@link StreamBufferPool}.
*/
public void writeHttpResponse(HttpVersion version, boolean isIncludeStackTrace, StreamBuffer head,
StreamBufferPool bufferPool) {
// Write the status line
version.write(head, bufferPool);
StreamBuffer.write(SPACE, head, bufferPool);
this.status.write(head, bufferPool);
StreamBuffer.write(HEADER_EOLN, head, bufferPool);
// Write the headers
for (int i = 0; i < this.headers.length; i++) {
this.headers[i].write(head, bufferPool);
}
// Determine if include the stack trace
if (!isIncludeStackTrace) {
// Complete request without entity
StreamBuffer.write(HEADER_EOLN, head, bufferPool);
return;
}
// Generate the stack trace
StringWriter stackTrace = new StringWriter();
PrintWriter writer = new PrintWriter(stackTrace);
this.printStackTrace(writer);
writer.flush();
byte[] stackTraceBytes = stackTrace.toString().getBytes(ServerHttpConnection.DEFAULT_HTTP_ENTITY_CHARSET);
// Write header for the content length
CONTENT_LENGTH.write(head, bufferPool);
StreamBuffer.write(COLON_SPACE, head, bufferPool);
StreamBuffer.write(stackTraceBytes.length, head, bufferPool);
StreamBuffer.write(HEADER_EOLN, head, bufferPool);
// Write end of headers
StreamBuffer.write(HEADER_EOLN, head, bufferPool);
// Write the stack trace
StreamBuffer.write(stackTraceBytes, head, bufferPool);
}
/**
* Allow error message.
*/
private static class ErrorMessageException extends Exception {
private static final long serialVersionUID = 1L;
/**
* Instantiate with error message.
*
* @param message Error message.
*/
private ErrorMessageException(String message) {
super(message);
}
}
/*
* ==================== Exception =====================
*/
@Override
public String getMessage() {
Throwable cause = this.getCause();
if ((cause != null) && (cause instanceof ErrorMessageException)) {
// Use just the error message
return cause.getMessage();
} else {
// Provide full message
return super.getMessage();
}
}
}