Observer協處理器通常在一個特定的事件（諸如Get或Put）之前或之後發生，相當於RDBMS中的觸發器。Endpoint協處理器則類似於RDBMS中的存儲過程，因為它可以讓你在RegionServer上對數據執行自定義計算，而不是在客戶端上執行計算。 本文是以上兩者的簡單實例，使用的環境：環境 ...
Observer協處理器通常在一個特定的事件（諸如Get或Put）之前或之後發生，相當於RDBMS中的觸發器。Endpoint協處理器則類似於RDBMS中的存儲過程，因為它可以讓你在RegionServer上對數據執行自定義計算，而不是在客戶端上執行計算。
本文是以上兩者的簡單實例，使用的環境：環境 jdk1.8 hadoop2.6.5 hbase1.2.4。
1、Endpoint實例
1> 編寫適用於protobuf的proto文件，如下，儘量不要帶註釋，因為編譯時可能出現亂碼
option java_package = "com.endpoint.test"; option java_outer_classname = "Sum"; option java_generic_services = true; option java_generate_equals_and_hash = true; option optimize_for = SPEED; message SumRequest { required string family = 1; required string column = 2; } message SumResponse { required int64 sum = 1 [default = 0]; } service SumService { rpc getSum(SumRequest) returns (SumResponse); }
2> 編譯上面的proto文件
使用protoc程式進行編譯，linux下或者windows均可，protoc程式可以直接從github下載:https://github.com/google/protobuf/releases，也可以自己編譯生成，參見protobuf的編譯安裝
註意，編譯的版本要與hadoop以及hbase使用的版本相同，或者略高，但最好不要過高，hadoop2.6.5 hbase1.2.4使用的都是protobuf2.5.0的版本，寫此篇文章時的最新版為3.1.0
（高版本必須指定syntax，例如proto3的syntax在第一行非空白非註釋行，必須寫：syntax = "proto3"，欄位規則移除了 “required”，並把 “optional” 改名為 “singular”,移除了 default 選項。可搜索Protobuf 的 proto3 與 proto2 的區別進行瞭解。）下載的話選擇帶win或linux的版本，這是編譯好的版本。有很多帶具體語言的版本，是一些具體某種語言的發行版源碼包。，為了與hbase以及hadoop統一起來，此處用的是protoc-2.5.0-win32.zip。
解壓文件：
使用windows命令行進入上面的目錄，執行以下命令即可：
protoc.exe sum1.proto --java_out=./
高版本有編譯好的適用於linux下的protoc程式文件，低版本沒有。在linux下執行以下命令：
protoc sum.proto --java_out=./
結果都一樣，生成的代碼參見摺疊部分，有很多，因為上面文件中指定java_outer_classname = "Sum"，所以會生成Sum類，將這個類引入到項目中，註意項目的包名稱與上面文件中指定（option java_package = "com.endpoint.test"）的名稱要一致。
1 // Generated by the protocol buffer compiler. DO NOT EDIT! 2 // source: sumcode.proto 3 4 package com.endpoint.test; 5 6 public final class Sum { 7 private Sum() {} 8 public static void registerAllExtensions( 9 com.google.protobuf.ExtensionRegistry registry) { 10 } 11 public interface SumRequestOrBuilder 12 extends com.google.protobuf.MessageOrBuilder { 13 14 // required string family = 1; 15 /** 16 * <code>required string family = 1;</code> 17 */ 18 boolean hasFamily(); 19 /** 20 * <code>required string family = 1;</code> 21 */ 22 java.lang.String getFamily(); 23 /** 24 * <code>required string family = 1;</code> 25 */ 26 com.google.protobuf.ByteString 27 getFamilyBytes(); 28 29 // required string column = 2; 30 /** 31 * <code>required string column = 2;</code> 32 */ 33 boolean hasColumn(); 34 /** 35 * <code>required string column = 2;</code> 36 */ 37 java.lang.String getColumn(); 38 /** 39 * <code>required string column = 2;</code> 40 */ 41 com.google.protobuf.ByteString 42 getColumnBytes(); 43 } 44 /** 45 * Protobuf type {@code SumRequest} 46 */ 47 public static final class SumRequest extends 48 com.google.protobuf.GeneratedMessage 49 implements SumRequestOrBuilder { 50 // Use SumRequest.newBuilder() to construct. 51 private SumRequest(com.google.protobuf.GeneratedMessage.Builder<?> builder) { 52 super(builder); 53 this.unknownFields = builder.getUnknownFields(); 54 } 55 private SumRequest(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); } 56 57 private static final SumRequest defaultInstance; 58 public static SumRequest getDefaultInstance() { 59 return defaultInstance; 60 } 61 62 public SumRequest getDefaultInstanceForType() { 63 return defaultInstance; 64 } 65 66 private final com.google.protobuf.UnknownFieldSet unknownFields; 67 @java.lang.Override 68 public final com.google.protobuf.UnknownFieldSet 69 getUnknownFields() { 70 return this.unknownFields; 71 } 72 private SumRequest( 73 com.google.protobuf.CodedInputStream input, 74 com.google.protobuf.ExtensionRegistryLite extensionRegistry) 75 throws com.google.protobuf.InvalidProtocolBufferException { 76 initFields(); 77 int mutable_bitField0_ = 0; 78 com.google.protobuf.UnknownFieldSet.Builder unknownFields = 79 com.google.protobuf.UnknownFieldSet.newBuilder(); 80 try { 81 boolean done = false; 82 while (!done) { 83 int tag = input.readTag(); 84 switch (tag) { 85 case 0: 86 done = true; 87 break; 88 default: { 89 if (!parseUnknownField(input, unknownFields, 90 extensionRegistry, tag)) { 91 done = true; 92 } 93 break; 94 } 95 case 10: { 96 bitField0_ |= 0x00000001; 97 family_ = input.readBytes(); 98 break; 99 } 100 case 18: { 101 bitField0_ |= 0x00000002; 102 column_ = input.readBytes(); 103 break; 104 } 105 } 106 } 107 } catch (com.google.protobuf.InvalidProtocolBufferException e) { 108 throw e.setUnfinishedMessage(this); 109 } catch (java.io.IOException e) { 110 throw new com.google.protobuf.InvalidProtocolBufferException( 111 e.getMessage()).setUnfinishedMessage(this); 112 } finally { 113 this.unknownFields = unknownFields.build(); 114 makeExtensionsImmutable(); 115 } 116 } 117 public static final com.google.protobuf.Descriptors.Descriptor 118 getDescriptor() { 119 return com.endpoint.test.Sum.internal_static_SumRequest_descriptor; 120 } 121 122 protected com.google.protobuf.GeneratedMessage.FieldAccessorTable 123 internalGetFieldAccessorTable() { 124 return com.endpoint.test.Sum.internal_static_SumRequest_fieldAccessorTable 125 .ensureFieldAccessorsInitialized( 126 com.endpoint.test.Sum.SumRequest.class, com.endpoint.test.Sum.SumRequest.Builder.class); 127 } 128 129 public static com.google.protobuf.Parser<SumRequest> PARSER = 130 new com.google.protobuf.AbstractParser<SumRequest>() { 131 public SumRequest parsePartialFrom( 132 com.google.protobuf.CodedInputStream input, 133 com.google.protobuf.ExtensionRegistryLite extensionRegistry) 134 throws com.google.protobuf.InvalidProtocolBufferException { 135 return new SumRequest(input, extensionRegistry); 136 } 137 }; 138 139 @java.lang.Override 140 public com.google.protobuf.Parser<SumRequest> getParserForType() { 141 return PARSER; 142 } 143 144 private int bitField0_; 145 // required string family = 1; 146 public static final int FAMILY_FIELD_NUMBER = 1; 147 private java.lang.Object family_; 148 /** 149 * <code>required string family = 1;</code> 150 */ 151 public boolean hasFamily() { 152 return ((bitField0_ & 0x00000001) == 0x00000001); 153 } 154 /** 155 * <code>required string family = 1;</code> 156 */ 157 public java.lang.String getFamily() { 158 java.lang.Object ref = family_; 159 if (ref instanceof java.lang.String) { 160 return (java.lang.String) ref; 161 } else { 162 com.google.protobuf.ByteString bs = 163 (com.google.protobuf.ByteString) ref; 164 java.lang.String s = bs.toStringUtf8(); 165 if (bs.isValidUtf8()) { 166 family_ = s; 167 } 168 return s; 169 } 170 } 171 /** 172 * <code>required string family = 1;</code> 173 */ 174 public com.google.protobuf.ByteString 175 getFamilyBytes() { 176 java.lang.Object ref = family_; 177 if (ref instanceof java.lang.String) { 178 com.google.protobuf.ByteString b = 179 com.google.protobuf.ByteString.copyFromUtf8( 180 (java.lang.String) ref); 181 family_ = b; 182 return b; 183 } else { 184 return (com.google.protobuf.ByteString) ref; 185 } 186 } 187 188 // required string column = 2; 189 public static final int COLUMN_FIELD_NUMBER = 2; 190 private java.lang.Object column_; 191 /** 192 * <code>required string column = 2;</code> 193 */ 194 public boolean hasColumn() { 195 return ((bitField0_ & 0x00000002) == 0x00000002); 196 } 197 /** 198 * <code>required string column = 2;</code> 199 */ 200 public java.lang.String getColumn() { 201 java.lang.Object ref = column_; 202 if (ref instanceof java.lang.String) { 203 return (java.lang.String) ref; 204 } else { 205 com.google.protobuf.ByteString bs = 206 (com.google.protobuf.ByteString) ref; 207 java.lang.String s = bs.toStringUtf8(); 208 if (bs.isValidUtf8()) { 209 column_ = s; 210 } 211 return s; 212 } 213 } 214 /** 215 * <code>required string column = 2;</code> 216 */ 217 public com.google.protobuf.ByteString 218 getColumnBytes() { 219 java.lang.Object ref = column_; 220 if (ref instanceof java.lang.String) { 221 com.google.protobuf.ByteString b = 222 com.google.protobuf.ByteString.copyFromUtf8( 223 (java.lang.String) ref); 224 column_ = b; 225 return b; 226 } else { 227 return (com.google.protobuf.ByteString) ref; 228 } 229 } 230 231 private void initFields() { 232 family_ = ""; 233 column_ = ""; 234 } 235 private byte memoizedIsInitialized = -1; 236 public final boolean isInitialized() { 237 byte isInitialized = memoizedIsInitialized; 238 if (isInitialized != -1) return isInitialized == 1; 239 240 if (!hasFamily()) { 241 memoizedIsInitialized = 0; 242 return false; 243 } 244 if (!hasColumn()) { 245 memoizedIsInitialized = 0; 246 return false; 247 } 248 memoizedIsInitialized = 1; 249 return true; 250 } 251 252 public void writeTo(com.google.protobuf.CodedOutputStream output) 253 throws java.io.IOException { 254 getSerializedSize(); 255 if (((bitField0_ & 0x00000001) == 0x00000001)) { 256 output.writeBytes(1, getFamilyBytes()); 257 } 258 if (((bitField0_ & 0x00000002) == 0x00000002)) { 259 output.writeBytes(2, getColumnBytes()); 260 } 261 getUnknownFields().writeTo(output); 262 } 263 264 private int memoizedSerializedSize = -1; 265 public int getSerializedSize() { 266 int size = memoizedSerializedSize; 267 if (size != -1) return size; 268 269 size = 0; 270 if (((bitField0_ & 0x00000001) == 0x00000001)) { 271 size += com.google.protobuf.CodedOutputStream 272 .computeBytesSize(1, getFamilyBytes()); 273 } 274 if (((bitField0_ & 0x00000002) == 0x00000002)) { 275 size += com.google.protobuf.CodedOutputStream 276 .computeBytesSize(2, getColumnBytes()); 277 } 278 size += getUnknownFields().getSerializedSize(); 279 memoizedSerializedSize = size; 280 return size; 281 } 282 283 private static final long serialVersionUID = 0L; 284 @java.lang.Override 285 protected java.lang.Object writeReplace() 286 throws java.io.ObjectStreamException { 287 return super.writeReplace(); 288 } 289 290 @java.lang.Override 291 public boolean equals(final java.lang.Object obj) { 292 if (obj == this) { 293 return true; 294 } 295 if (!(obj instanceof com.endpoint.test.Sum.SumRequest)) { 296 return super.equals(obj); 297 } 298 com.endpoint.test.Sum.SumRequest other = (com.endpoint.test.Sum.SumRequest) obj; 299 300 boolean result = true; 301 result = result && (hasFamily() == other.hasFamily()); 302 if (hasFamily()) { 303 result = result && getFamily() 304 .equals(other.getFamily()); 305 } 306 result = result && (hasColumn() == other.hasColumn()); 307 if (hasColumn()) { 308 result = result && getColumn() 309 .equals(other.getColumn()); 310 } 311 result = result && 312 getUnknownFields().equals(other.getUnknownFields()); 313 return result; 314 } 315 316 private int memoizedHashCode = 0; 317 @java.lang.Override 318 public int hashCode() { 319 if (memoizedHashCode != 0) { 320 return memoizedHashCode; 321 } 322 int hash = 41; 323 hash = (19 * hash) + getDescriptorForType().hashCode(); 324 if (hasFamily()) { 325 hash = (37 * hash) + FAMILY_FIELD_NUMBER; 326 hash = (53 * hash) + getFamily().hashCode(); 327 } 328 if (hasColumn()) { 329 hash = (37 * hash) + COLUMN_FIELD_NUMBER; 330 hash = (53 * hash) + getColumn().hashCode(); 331 } 332 hash = (29 * hash) + getUnknownFields().hashCode(); 333 memoizedHashCode = hash; 334 return hash; 335 } 336 337 public static com.endpoint.test.Sum.SumRequest parseFrom( 338 com.google.protobuf.ByteString data) 339 throws com.google.protobuf.InvalidProtocolBufferException { 340 return PARSER.parseFrom(data); 341 } 342 public static com.endpoint.test.Sum.SumRequest parseFrom( 343 com.google.protobuf.ByteString data, 344 com.google.protobuf.ExtensionRegistryLite extensionRegistry) 345 throws com.google.protobuf.InvalidProtocolBufferException { 346 return PARSER.parseFrom(data, extensionRegistry); 347 } 348 public static com.endpoint.test.Sum.SumRequest parseFrom(byte[] data) 349 throws com.google.protobuf.InvalidProtocolBufferException { 350 return PARSER.parseFrom(data); 351 } 352 public static com.endpoint.test.Sum.SumRequest parseFrom( 353 byte[] data, 354 com.google.protobuf.ExtensionRegistryLite extensionRegistry) 355 throws com.google.protobuf.InvalidProtocolBufferException { 356 return PARSER.parseFrom(data, extensionRegistry); 357 } 358 public static com.endpoint.test.Sum.SumRequest parseFrom(java.io.InputStream input) 359 throws java.io.IOException { 360 return PARSER.parseFrom(input); 361 } 362 public static com.endpoint.test.Sum.SumRequest parseFrom( 363 java.io.InputStream input, 364 com.google.protobuf.ExtensionRegistryLite extensionRegistry) 365 throws java.io.IOException { 366 return PARSER.parseFrom(input, extensionRegistry); 367 } 368 public static com.endpoint.test.Sum.SumRequest parseDelimitedFrom(java.io.InputStream input) 369 throws java.io.IOException { 370 return PARSER.parseDelimitedFrom(input); 371 } 372 public static com.endpoint.test.Sum.SumRequest parseDelimitedFrom( 373 java.io.InputStream input, 374 com.google.protobuf.ExtensionRegistryLite extensionRegistry) 375 throws java.io.IOException { 376 return PARSER.parseDelimitedFrom(input, extensionRegistry); 377 } 378 public static com.endpoint.test.Sum.SumRequest parseFrom( 379 com.google.protobuf.CodedInputStream input) 380 throws java.io.IOException { 381 return PARSER.parseFrom(input); 382 } 383 public static com.endpoint.test.Sum.SumRequest parseFrom( 384 com.google.protobuf.CodedInputStream input, 385 com.google.protobuf.ExtensionRegistryLite extensionRegistry) 386 throws java.io.IOException { 387 return PARSER.parseFrom(input, extensionRegistry); 388 } 389 390 public static Builder newBuilder() { return Builder.create(); } 391 public Builder newBuilderForType() { return newBuilder(); } 392 public static Builder newBuilder(com.endpoint.test.Sum.SumRequest prototype) { 393 return newBuilder().mergeFrom(prototype); 394 } 395 public Builder toBuilder() { return newBuilder(this); } 396 397 @java.lang.Override 398 protected Builder newBuilderForType( 399 com.google.protobuf.GeneratedMessage.BuilderParent parent) { 400 Builder builder = new Builder(parent); 401 return builder; 402 } 403 /** 404 * Protobuf type {@code SumRequest} 405 */ 406 public static final class Builder extends 407 com.google.protobuf.GeneratedMessage.Builder<Builder> 408 implements com.endpoint.test.Sum.SumRequestOrBuilder { 409 public static final com.google.protobuf.Descriptors.Descriptor 410 getDescriptor() { 411 return com.endpoint.test.Sum.internal_static_SumRequest_descriptor; 412 } 413 414 protected com.google.protobuf.GeneratedMessage.FieldAccessorTable 415 internalGetFieldAccessorTable() { 416 return com.endpoint.test.Sum.internal_static_SumRequest_fieldAccessorTable 417 .ensureFieldAccessorsInitialized( 418 com.endpoint.test.Sum.SumRequest.class, com.endpoint.test.Sum.SumRequest.Builder.class); 419 } 420 421 // Construct using com.endpoint.test.Sum.SumRequest.newBuilder() 422 private Builder() { 423 maybeForceBuilderInitialization(); 424 } 425 426 private Builder( 427 com.google.protobuf.GeneratedMessage.BuilderParent parent) { 428 super(parent); 429 maybeForceBuilderInitialization(); 430 } 431 private void maybeForceBuilderInitialization() { 432 if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) { 433 } 434 } 435 private static Builder create() { 436 return new Builder(); 437 } 438 439 public Builder clear() { 440 super.clear(); 441 family_ = ""; 442 bitField0_ = (bitField0_ & ~0x00000001); 443 column_ = ""; 444 bitField0_ = (bitField0_ & ~0x00000002); 445 return this; 446 } 447 448 public Builder clone() { 449 return create().mergeFrom(buildPartial()); 450 } 451 452 public com.google.protobuf.Descriptors.Descriptor 453 getDescriptorForType() { 454 return com.endpoint.test.Sum.internal_static_SumRequest_descriptor; 455 } 456 457 public com.endpoint.test.Sum.SumRequest getDefaultInstanceForType() { 458 return com.endpoint.test.Sum.SumRequest.getDefaultInstance(); 459 } 460 461 public com.endpoint.test.Sum.SumRequest build() { 462 com.endpoint.test.Sum.SumRequest result = buildPartial(); 463 if (!result.isInitialized()) { 464 throw newUninitializedMessageException(result); 465 } 466 return result; 467 } 468 469
