0
# HTTP and Protocol Connectors
1

2
Coyote connector architecture provides protocol handlers for HTTP/1.1, HTTP/2, and AJP protocols. Connectors manage network I/O, thread pools, connection limits, and protocol-specific processing to efficiently handle incoming requests and generate responses.
3

4
## Capabilities
5

6
### Connector Class
7

8
Main connector implementation managing protocol handlers and network configuration.
9

10
```java { .api }
11
public class Connector extends LifecycleMBeanBase {
12
    // Constructors
13
    public Connector();
14
    public Connector(String protocol);
15
    public Connector(ProtocolHandler protocolHandler);
16

17
    // Protocol configuration
18
    public String getProtocol();
19
    public String getProtocolHandlerClassName();
20
    public ProtocolHandler getProtocolHandler();
21

22
    // Network configuration
23
    public int getPort();
24
    public void setPort(int port);
25
    public int getPortOffset();
26
    public void setPortOffset(int portOffset);
27
    public int getPortWithOffset();
28
    public int getLocalPort();
29

30
    // Scheme and security
31
    public String getScheme();
32
    public void setScheme(String scheme);
33
    public boolean getSecure();
34
    public void setSecure(boolean secure);
35

36
    // Async timeout configuration
37
    public long getAsyncTimeout();
38
    public void setAsyncTimeout(long asyncTimeout);
39

40
    // Request configuration
41
    public int getMaxPostSize();
42
    public void setMaxPostSize(int maxPostSize);
43
    public int getMaxSavePostSize();
44
    public void setMaxSavePostSize(int maxSavePostSize);
45
    public int getMaxParameterCount();
46
    public void setMaxParameterCount(int maxParameterCount);
47
    public int getMaxCookieCount();
48
    public void setMaxCookieCount(int maxCookieCount);
49
    public String getParseBodyMethods();
50
    public void setParseBodyMethods(String methods);
51

52
    // Encoding
53
    public String getURIEncoding();
54
    public void setURIEncoding(String URIEncoding);
55
    public Charset getURICharset();
56
    public boolean getUseBodyEncodingForURI();
57
    public void setUseBodyEncodingForURI(boolean useBodyEncodingForURI);
58
    public String getEncodedSolidusHandling();
59
    public void setEncodedSolidusHandling(String encodedSolidusHandling);
60
    public String getEncodedReverseSolidusHandling();
61
    public void setEncodedReverseSolidusHandling(String encodedReverseSolidusHandling);
62

63
    // Proxy configuration
64
    public String getProxyName();
65
    public void setProxyName(String proxyName);
66
    public int getProxyPort();
67
    public void setProxyPort(int proxyPort);
68

69
    // Redirect configuration
70
    public int getRedirectPort();
71
    public void setRedirectPort(int redirectPort);
72
    public int getRedirectPortWithOffset();
73

74
    // Service reference
75
    public Service getService();
76
    public void setService(Service service);
77

78
    // Request/Response creation
79
    public Request createRequest();
80
    public Response createResponse();
81

82
    // Protocol handler properties (delegated via reflection)
83
    public boolean setProperty(String name, String value);
84
    public Object getProperty(String name);
85

86
    // Utility configuration
87
    public boolean getAllowBackslash();
88
    public void setAllowBackslash(boolean allowBackslash);
89
    public boolean getAllowTrace();
90
    public void setAllowTrace(boolean allowTrace);
91
    public boolean getEnableLookups();
92
    public void setEnableLookups(boolean enableLookups);
93
    public boolean getDiscardFacades();
94
    public void setDiscardFacades(boolean discardFacades);
95
    public boolean getEnforceEncodingInGetWriter();
96
    public void setEnforceEncodingInGetWriter(boolean enforceEncodingInGetWriter);
97
    public boolean getXpoweredBy();
98
    public void setXpoweredBy(boolean xpoweredBy);
99
    public boolean getUseIPVHosts();
100
    public void setUseIPVHosts(boolean useIPVHosts);
101
    public boolean getRejectSuspiciousURIs();
102
    public void setRejectSuspiciousURIs(boolean rejectSuspiciousURIs);
103

104
    // SSL configuration
105
    public void addSslHostConfig(SSLHostConfig sslHostConfig);
106
    public SSLHostConfig[] findSslHostConfigs();
107

108
    // Protocol upgrades
109
    public void addUpgradeProtocol(UpgradeProtocol upgradeProtocol);
110
    public UpgradeProtocol[] findUpgradeProtocols();
111

112
    // Executor
113
    public String getExecutorName();
114
    public void setExecutorName(String executorName);
115

116
    // Lifecycle methods
117
    public void init() throws LifecycleException;
118
    public void start() throws LifecycleException;
119
    public void stop() throws LifecycleException;
120
    public void destroy() throws LifecycleException;
121
    public void pause();
122
    public void resume();
123
    public LifecycleState getState();
124
    public String getStateName();
125

126
    // Management
127
    public String getDomain();
128
    public ObjectName getObjectName();
129

130
    // Lifecycle listeners
131
    public void addLifecycleListener(LifecycleListener listener);
132
    public void removeLifecycleListener(LifecycleListener listener);
133
    public LifecycleListener[] findLifecycleListeners();
134
}
135
```
136

137
### Protocol Handler Properties
138

139
The `Connector` class delegates many configuration properties to its underlying `ProtocolHandler` using the `setProperty(String name, String value)` method. Common properties include:
140

141
- **maxThreads**: Maximum number of request processing threads (default: 200)
142
- **minSpareThreads**: Minimum number of spare threads (default: 10)
143
- **maxConnections**: Maximum number of connections (default: 8192 for NIO)
144
- **acceptCount**: Maximum queue length for incoming connections (default: 100)
145
- **connectionTimeout**: Network connection timeout in milliseconds (default: 20000)
146
- **keepAliveTimeout**: Keep-alive timeout in milliseconds (default: connectionTimeout)
147
- **maxKeepAliveRequests**: Maximum keep-alive requests per connection (default: 100)
148
- **compression**: Enable compression ("on", "off", "force")
149
- **compressionMinSize**: Minimum response size to compress (default: 2048)
150
- **compressibleMimeType**: MIME types to compress (default: text/html,text/xml,text/plain,text/css,text/javascript,application/javascript)
151
- **address**: Network address to bind (default: all addresses)
152

153
These properties are accessed via reflection on the `ProtocolHandler` implementation.
154

155
### Protocol Handlers
156

157
Base interfaces for protocol implementations.
158

159
```java { .api }
160
public interface ProtocolHandler {
161
    // Configuration
162
    public void setAdapter(Adapter adapter);
163
    public Adapter getAdapter();
164
    
165
    // Executor
166
    public Executor getExecutor();
167
    
168
    // Lifecycle
169
    public void init() throws Exception;
170
    public void start() throws Exception;
171
    public void pause() throws Exception;
172
    public void resume() throws Exception;
173
    public void stop() throws Exception;
174
    public void destroy() throws Exception;
175

176
    // Socket utilities
177
    public boolean isSendfileSupported();
178
}
179

180
public interface Adapter {
181
    public void service(org.apache.coyote.Request req, org.apache.coyote.Response res) 
182
        throws Exception;
183
    public boolean prepare(org.apache.coyote.Request req, org.apache.coyote.Response res) 
184
        throws Exception;
185
    public boolean asyncDispatch(org.apache.coyote.Request req, org.apache.coyote.Response res, 
186
        SocketEvent status) throws Exception;
187
    public void log(org.apache.coyote.Request req, org.apache.coyote.Response res, long time);
188
    public void checkRecycled(org.apache.coyote.Request req, org.apache.coyote.Response res);
189
    public String getDomain();
190
}
191
```
192

193
### Coyote Request and Response
194

195
Low-level request/response objects used by protocol handlers.
196

197
```java { .api }
198
// Coyote Request
199
public final class Request {
200
    // Request line
201
    public MessageBytes method();
202
    public MessageBytes requestURI();
203
    public MessageBytes decodedURI();
204
    public MessageBytes queryString();
205
    public MessageBytes protocol();
206
    
207
    // Headers
208
    public MimeHeaders getMimeHeaders();
209
    public int getServerPort();
210
    public void setServerPort(int port);
211
    public MessageBytes serverName();
212
    
213
    // Request body
214
    public InputBuffer getInputBuffer();
215
    public void setInputBuffer(InputBuffer inputBuffer);
216
    public int doRead(ApplicationBufferHandler handler) throws IOException;
217
    public int getAvailable();
218
    public boolean isFinished();
219
    
220
    // Attributes
221
    public void setAttribute(String name, Object o);
222
    public Object getAttribute(String name);
223

224
    // Content
225
    public long getContentLengthLong();
226
    public String getContentType();
227

228
    // Connection
229
    public MessageBytes remoteAddr();
230
    public MessageBytes remoteHost();
231
    public int getRemotePort();
232
    public MessageBytes localAddr();
233
    public int getLocalPort();
234
    public MessageBytes localName();
235
    
236
    // Lifecycle
237
    public void recycle();
238
    
239
    // Async
240
    public boolean isAsync();
241
}
242

243
// Coyote Response
244
public final class Response {
245
    // Status
246
    public void setStatus(int status);
247
    public int getStatus();
248
    public String getMessage();
249
    public void setMessage(String message);
250
    
251
    // Headers
252
    public MimeHeaders getMimeHeaders();
253
    public void setContentLength(long length);
254
    public long getContentLength();
255
    public void setContentType(String type);
256
    public String getContentType();
257
    
258
    // Response body
259
    public OutputBuffer getOutputBuffer();
260
    public void setOutputBuffer(OutputBuffer outputBuffer);
261
    public int doWrite(ByteBuffer chunk) throws IOException;
262
    
263
    // State
264
    public boolean isCommitted();
265
    public void setCommitted(boolean committed);
266
    public void action(ActionCode actionCode, Object param);
267
    
268
    // Error
269
    public void setErrorException(Exception ex);
270
    public Exception getErrorException();
271
    
272
    // Lifecycle
273
    public void recycle();
274
    
275
    // Async
276
    public boolean isAsync();
277
}
278
```
279

280
## Usage Examples
281

282
### Custom Connector Configuration
283

284
```java
285
import org.apache.catalina.startup.Tomcat;
286
import org.apache.catalina.connector.Connector;
287

288
public class ConnectorConfigExample {
289
    public static void main(String[] args) throws Exception {
290
        Tomcat tomcat = new Tomcat();
291

292
        // HTTP/1.1 NIO connector
293
        Connector connector = new Connector("HTTP/1.1");
294
        connector.setPort(8080);
295
        connector.setScheme("http");
296

297
        // Configure protocol handler properties via setProperty
298
        connector.setProperty("maxThreads", "200");
299
        connector.setProperty("minSpareThreads", "10");
300
        connector.setProperty("maxConnections", "10000");
301
        connector.setProperty("connectionTimeout", "20000");
302
        connector.setProperty("compression", "on");
303
        connector.setProperty("compressionMinSize", "2048");
304
        connector.setProperty("compressibleMimeType",
305
            "text/html,text/xml,text/plain,text/css,application/json");
306

307
        tomcat.setConnector(connector);
308
        tomcat.start();
309
        tomcat.getServer().await();
310
    }
311
}
312
```
313