Apache Avro是一个独立与编程语言的数据序列化系统，该项目由Doug Cutting（Hadoop之父）牵头创建的。它可以提供：
- 丰富的数据结构类型
- 快速可压缩的二进制数据形式
- 存储持久数据的文件容器
- 远程过程调用（RPC）
- 同动态语言的简单集成。读写数据文件和使用RPC协议都不需要生成代码，而代码生成作为一种可选的优化只值得在静态类型语言中实现。
今天尝试一下Apache Avro支持的各种数据类型。
test.avsc
{"namespace": "com.yqu.avro",
"type": "record",
"name": "Test",
"fields": [
{"name": "stringVar", "type": "string"},
{"name": "bytesVar", "type": ["bytes", "null"]},
{"name": "booleanVar", "type": "boolean"},
{"name": "intVar", "type": "int", "order":"descending"},
{"name": "longVar", "type": ["long", "null"], "order":"ascending"},
{"name": "floatVar", "type": "float"},
{"name": "doubleVar", "type": "double"},
{"name": "enumVar", "type": {"type": "enum", "name": "Suit", "symbols" : ["SPADES", "HEARTS", "DIAMONDS", "CLUBS"]}},
{"name": "strArrayVar", "type": {"type": "array", "items": "string"}},
{"name": "intArrayVar", "type": {"type": "array", "items": "int"}},
{"name": "mapVar", "type": {"type": "map", "values": "long"}},
{"name": "fixedVar", "type": {"type": "fixed", "size": 16, "name": "md5"}}
]
}
使用下列命令将schema编译成代码
java -jar avro-tools-1.7.5.jar compile schema test.avsc .
Test.java
package com.yqu.avro;
@SuppressWarnings("all")
@org.apache.avro.specific.AvroGenerated
public class Test extends org.apache.avro.specific.SpecificRecordBase implements org.apache.avro.specific.SpecificRecord {
public static final org.apache.avro.Schema SCHEMA$ =
new org.apache.avro.Schema.Parser().parse(
"{"type":"record","name":"Test","namespace":"com.yqu.avro","fields":[{"name":"stringVar","type":"string"},{"name":"bytesVar","type":["bytes","null"]},{"name":"booleanVar","type":"boolean"},{"name":"intVar","type":"int","order":"descending"},{"name":"longVar","type":["long","null"]},{"name":"floatVar","type":"float"},{"name":"doubleVar","type":"double"},{"name":"enumVar","type":{"type":"enum","name":"Suit","symbols":["SPADES","HEARTS","DIAMONDS","CLUBS"]}},{"name":"strArrayVar","type":{"type":"array","items":"string"}},{"name":"intArrayVar","type":{"type":"array","items":"int"}},{"name":"mapVar","type":{"type":"map","values":"long"}},{"name":"fixedVar","type":{"type":"fixed","name":"md5","size":16}}]}");
public static org.apache.avro.Schema getClassSchema() { return SCHEMA$; }
@Deprecated public java.lang.CharSequence stringVar;
@Deprecated public java.nio.ByteBuffer bytesVar;
@Deprecated public boolean booleanVar;
@Deprecated public int intVar;
@Deprecated public java.lang.Long longVar;
@Deprecated public float floatVar;
@Deprecated public double doubleVar;
@Deprecated public com.yqu.avro.Suit enumVar;
@Deprecated public java.util.List<java.lang.charsequence> strArrayVar;
@Deprecated public java.util.List<java.lang.integer> intArrayVar;
@Deprecated public java.util.Map<java.lang.charsequence,java.lang.long> mapVar;
@Deprecated public com.yqu.avro.md5 fixedVar;
public Test() {}
public Test(java.lang.CharSequence stringVar, java.nio.ByteBuffer bytesVar,
java.lang.Boolean booleanVar, java.lang.Integer intVar, java.lang.Long longVar,
java.lang.Float floatVar, java.lang.Double doubleVar, com.yqu.avro.Suit enumVar,
java.util.List<java.lang.charsequence> strArrayVar,
java.util.List<java.lang.integer> intArrayVar,
java.util.Map<java.lang.charsequence,java.lang.long> mapVar,
com.yqu.avro.md5 fixedVar) {
this.stringVar = stringVar;
this.bytesVar = bytesVar;
this.booleanVar = booleanVar;
this.intVar = intVar;
this.longVar = longVar;
this.floatVar = floatVar;
this.doubleVar = doubleVar;
this.enumVar = enumVar;
this.strArrayVar = strArrayVar;
this.intArrayVar = intArrayVar;
this.mapVar = mapVar;
this.fixedVar = fixedVar;
}
public org.apache.avro.Schema getSchema() { return SCHEMA$; }
// Used by DatumWriter. Applications should not call.
public {
switch (field$) {
case 0: return stringVar;
case 1: return bytesVar;
case 2: return booleanVar;
case 3: return intVar;
case 4: return longVar;
case 5: return floatVar;
case 6: return doubleVar;
case 7: return enumVar;
case 8: return strArrayVar;
case 9: return intArrayVar;
case 10: return mapVar;
case 11: return fixedVar;
default: throw new org.apache.avro.AvroRuntimeException("Bad index");
}
}
// Used by DatumReader. Applications should not call.
@SuppressWarnings(value="unchecked")
public void put(int field$, {
switch (field$) {
case 0: stringVar = (value$; break;
case 1: bytesVar = (value$; break;
case 2: booleanVar = (value$; break;
case 3: intVar = (value$; break;
case 4: longVar = (value$; break;
case 5: floatVar = (value$; break;
case 6: doubleVar = (value$; break;
case 7: enumVar = (com.yqu.avro.Suit)value$; break;
case 8: strArrayVar = (value$; break;
case 9: intArrayVar = (value$; break;
case 10: mapVar = (value$; break;
case 11: fixedVar = (com.yqu.avro.md5)value$; break;
default: throw new org.apache.avro.AvroRuntimeException("Bad index");
}
}
public java.lang.CharSequence getStringVar() {
return stringVar;
}
public void setStringVar(java.lang.CharSequence value) {
this.stringVar = value;
}
public java.nio.ByteBuffer getByteVar() {
return bytesVar;
}
public void setBytesVar(java.nio.ByteBuffer value) {
this.bytesVar = value;
}
public boolean getBooleanVar) {
return booleanVar;
}
public void setBooleanVar(boolean value) {
this.booleanVar = value;
}
public int getIntVar() {
return intVar;
}
public void setIntVar(int value) {
this.intVar = value;
}
public long getLongVar() {
return longVar;
}
public void setLongVar(long value) {
this.longVar = value;
}
public float getFloatVar() {
return floatVar;
}
public void setFloatVar(float value) {
this.floatVar = value;
}
public double getDoubleVar() {
return doubleVar;
}
public void setDoubleVar(double value) {
this.doubleVar = value;
}
public com.yqu.avro.Suit getEnumVar() {
return enumVar;
}
public void setEnumVar(com.yqu.avro.Suit value) {
this.enumVar = value;
}
public java.util.List<java.lang.charsequence> getStrArrayVar() {
return strArrayVar;
}
public void setStrArrayVar(java.util.List<java.lang.charsequence> value) {
this.strArrayVar = value;
}
public public java.util.List<java.lang.integer> getIntArrayVar() {
return intArrayVar;
}
public void setIntArrayVar(java.util.List<java.lang.integer> value) {
this.intArrayVar = value;
}
public java.util.Map<java.lang.charsequence,java.lang.long> getMapVar() {
return mapVar;
}
public void setMapVar(java.util.Map<java.lang.charsequence,java.lang.long> value) {
this.mapVar = value;
}
public com.yqu.avro.md5 getFixedVar() {
return fixedVar;
}
public void setFixedVar(com.yqu.avro.md5 value) {
this.fixedVar = value;
}
public static com.yqu.avro.Test.Builder newBuilder() {
return new com.yqu.avro.Test.Builder();
}
public static com.yqu.avro.Test.Builder newBuilder(com.yqu.avro.Test.Builder other) {
return new com.yqu.avro.Test.Builder(other);
}
public static com.yqu.avro.Test.Builder newBuilder(com.yqu.avro.Test other) {
return new com.yqu.avro.Test.Builder(other);
}
public static class Builder extends org.apache.avro.specific.SpecificRecordBuilderBase<test>
implements org.apache.avro.data.RecordBuilder<test> {
private java.lang.CharSequence stringVar;
private java.nio.ByteBuffer bytesVar;
private boolean booleanVar;
private int intVar;
private java.lang.Long longVar;
private float floatVar;
private double doubleVar;
private com.yqu.avro.Suit enumVar;
private java.util.List<java.lang.charsequence> strArrayVar;
private java.util.List<java.lang.integer> intArrayVar;
private java.util.Map<java.lang.charsequence,java.lang.long> mapVar;
private com.yqu.avro.md5 fixedVar;
private Builder() {
super(com.yqu.avro.Test.SCHEMA$);
}
private Builder(com.yqu.avro.Test.Builder other) {
super(other);
if (isValidValue(fields()[0], other.stringVar)) {
this.stringVar = data().deepCopy(fields()[0].schema(), other.stringVar);
fieldSetFlags()[0] = true;
}
if (isValidValue(fields()[1], other.bytesVar)) {
this.bytesVar = data().deepCopy(fields()[1].schema(), other.bytesVar);
fieldSetFlags()[1] = true;
}
if (isValidValue(fields()[2], other.booleanVar)) {
this.booleanVar = data().deepCopy(fields()[2].schema(), other.booleanVar);
fieldSetFlags()[2] = true;
}
if (isValidValue(fields()[3], other.intVar)) {
this.intVar = data().deepCopy(fields()[3].schema(), other.intVar);
fieldSetFlags()[3] = true;
}
if (isValidValue(fields()[4], other.longVar)) {
this.longVar = data().deepCopy(fields()[4].schema(), other.longVar);
fieldSetFlags()[4] = true;
}
if (isValidValue(fields()[5], other.floatVar)) {
this.floatVar = data().deepCopy(fields()[5].schema(), other.floatVar);
fieldSetFlags()[5] = true;
}
if (isValidValue(fields()[6], other.doubleVar)) {
this.doubleVar = data().deepCopy(fields()[6].schema(), other.doubleVar);
fieldSetFlags()[6] = true;
}
if (isValidValue(fields()[7], other.enumVar)) {
this.enumVar = data().deepCopy(fields()[7].schema(), other.enumVar);
fieldSetFlags()[7] = true;
}
if (isValidValue(fields()[8], other.strArrayVar)) {
this.strArrayVar = data().deepCopy(fields()[8].schema(), other.strArrayVar);
fieldSetFlags()[8] = true;
}
if (isValidValue(fields()[9], other.intArrayVar)) {
this.intArrayVar = data().deepCopy(fields()[9].schema(), other.intArrayVar);
fieldSetFlags()[9] = true;
}
if (isValidValue(fields()[10], other.mapVar)) {
this.mapVar = data().deepCopy(fields()[10].schema(), other.mapVar);
fieldSetFlags()[10] = true;
}
if (isValidValue(fields()[11], other.fixedVar)) {
this.fixedVar = data().deepCopy(fields()[11].schema(), other.fixedVar);
fieldSetFlags()[11] = true;
}
}
private Builder(com.yqu.avro.Test other) {
super(com.yqu.avro.Test.SCHEMA$);
if (isValidValue(fields()[0], other.stringVar)) {
this.stringVar = data().deepCopy(fields()[0].schema(), other.stringVar);
fieldSetFlags()[0] = true;
}
if (isValidValue(fields()[1], other.bytesVar)) {
this.bytesVar = data().deepCopy(fields()[1].schema(), other.bytesVar);
fieldSetFlags()[1] = true;
}
if (isValidValue(fields()[2], other.booleanVar)) {
this.booleanVar = data().deepCopy(fields()[2].schema(), other.booleanVar);
fieldSetFlags()[2] = true;
}
if (isValidValue(fields()[3], other.intVar)) {
this.intVar = data().deepCopy(fields()[3].schema(), other.intVar);
fieldSetFlags()[3] = true;
}
if (isValidValue(fields()[4], other.longVar)) {
this.longVar = data().deepCopy(fields()[4].schema(), other.longVar);
fieldSetFlags()[4] = true;
}
if (isValidValue(fields()[5], other.floatVar)) {
this.floatVar = data().deepCopy(fields()[5].schema(), other.floatVar);
fieldSetFlags()[5] = true;
}
if (isValidValue(fields()[6], other.doubleVar)) {
this.doubleVar = data().deepCopy(fields()[6].schema(), other.doubleVar);
fieldSetFlags()[6] = true;
}
if (isValidValue(fields()[7], other.enumVar)) {
this.enumVar = data().deepCopy(fields()[7].schema(), other.enumVar);
fieldSetFlags()[7] = true;
}
if (isValidValue(fields()[8], other.strArrayVar)) {
this.strArrayVar = data().deepCopy(fields()[8].schema(), other.strArrayVar);
fieldSetFlags()[8] = true;
}
if (isValidValue(fields()[9], other.intArrayVar)) {
this.intArrayVar = data().deepCopy(fields()[9].schema(), other.intArrayVar);
fieldSetFlags()[9] = true;
}
if (isValidValue(fields()[10], other.mapVar)) {
this.mapVar = data().deepCopy(fields()[10].schema(), other.mapVar);
fieldSetFlags()[10] = true;
}
if (isValidValue(fields()[11], other.fixedVar)) {
this.fixedVar = data().deepCopy(fields()[11].schema(), other.fixedVar);
fieldSetFlags()[11] = true;
}
}
public java.lang.CharSequence getStringVar {
return stringVar;
}
public com.yqu.avro.Test.Builder setStringVar(java.lang.CharSequence value) {
validate(fields()[0], value);
this.stringVar = value;
fieldSetFlags()[0] = true;
return this;
}
public boolean hasStringVar() {
return fieldSetFlags()[0];
}
public com.yqu.avro.Test.Builder clearStringVar() {
stringVar = null;
fieldSetFlags()[0] = false;
return this;
}
public java.nio.ByteBuffer getByteVar() {
return bytesVar;
}
public com.yqu.avro.Test.Builder setBytesVar(java.nio.ByteBuffer value) {
validate(fields()[1], value);
this.bytesVar = value;
fieldSetFlags()[1] = true;
return this;
}
public boolean hasBytesVar() {
return fieldSetFlags()[1];
}
public com.yqu.avro.Test.Builder clearBytesVar() {
bytesVar = null;
fieldSetFlags()[1] = false;
return this;
}
public boolean getBooleanVar() {
return booleanVar;
}
public com.yqu.avro.Test.Builder setBooleanVar(boolean value) {
validate(fields()[2], value);
this.booleanVar = value;
fieldSetFlags()[2] = true;
return this;
}
public boolean hasBooleanVar() {
return fieldSetFlags()[2];
}
public com.yqu.avro.Test.Builder clearBooleanVar() {
fieldSetFlags()[2] = false;
return this;
}
public int getIntVar() {
return intVar;
}
public com.yqu.avro.Test.Builder setIntVar(int value) {
validate(fields()[3], value);
this.intVar = value;
fieldSetFlags()[3] = true;
return this;
}
public boolean hasIntVar() {
return fieldSetFlags()[3];
}
public com.yqu.avro.Test.Builder clearIntVar() {
fieldSetFlags()[3] = false;
return this;
}
public long getLongVar() {
return longVar;
}
public com.yqu.avro.Test.Builder setLongVar(long value) {
validate(fields()[4], value);
this.longVar = value;
fieldSetFlags()[4] = true;
return this;
}
public boolean hasLongVar() {
return fieldSetFlags()[4];
}
public com.yqu.avro.Test.Builder clearLongVar() {
longVar = null;
fieldSetFlags()[4] = false;
return this;
}
public float getFloatVar() {
return floatVar;
}
public com.yqu.avro.Test.Builder setFloatVar(float value) {
validate(fields()[5], value);
this.floatVar = value;
fieldSetFlags()[5] = true;
return this;
}
public boolean hasFloatVar() {
return fieldSetFlags()[5];
}
public com.yqu.avro.Test.Builder clearFloatVar() {
fieldSetFlags()[5] = false;
return this;
}
public double getDoubleVar() {
return doubleVar;
}
public com.yqu.avro.Test.Builder setDoubleVar(double value) {
validate(fields()[6], value);
this.doubleVar = value;
fieldSetFlags()[6] = true;
return this;
}
public boolean hasDoubleVar() {
return fieldSetFlags()[6];
}
public com.yqu.avro.Test.Builder clearDoubleVar() {
fieldSetFlags()[6] = false;
return this;
}
public com.yqu.avro.Suit getEnumVar() {
return enumVar;
}
public com.yqu.avro.Test.Builder setEnumVar(com.yqu.avro.Suit value) {
validate(fields()[7], value);
this.enumVar = value;
fieldSetFlags()[7] = true;
return this;
}
public boolean hasEnumVar() {
return fieldSetFlags()[7];
}
public com.yqu.avro.Test.Builder clearEnumVar() {
enumVar = null;
fieldSetFlags()[7] = false;
return this;
}
public java.util.List<java.lang.charsequence> getStrArrayVar() {
return strArrayVar;
}
public com.yqu.avro.Test.Builder setStrArrayVar(java.util.List<java.lang.charsequence> value) {
validate(fields()[8], value);
this.strArrayVar = value;
fieldSetFlags()[8] = true;
return this;
}
public boolean hasStrArrayVar() {
return fieldSetFlags()[8];
}
public com.yqu.avro.Test.Builder clearStrArrayVar() {
strArrayVar = null;
fieldSetFlags()[8] = false;
return this;
}
public java.util.List<java.lang.integer> getIntArrayVar() {
return intArrayVar;
}
public com.yqu.avro.Test.Builder setIntArrayVar(java.util.List<java.lang.integer> value) {
validate(fields()[9], value);
this.intArrayVar = value;
fieldSetFlags()[9] = true;
return this;
}
public boolean hasIntArrayVar() {
return fieldSetFlags()[9];
}
public com.yqu.avro.Test.Builder clearIntArrayVar() {
intArrayVar = null;
fieldSetFlags()[9] = false;
return this;
}
public java.util.Map<java.lang.charsequence,java.lang.long> getMapVar() {
return mapVar;
}
public com.yqu.avro.Test.Builder setMapVar(java.util.Map<java.lang.charsequence,java.lang.long> value) {
validate(fields()[10], value);
this.mapVar = value;
fieldSetFlags()[10] = true;
return this;
}
public boolean hasMapVar() {
return fieldSetFlags()[10];
}
public com.yqu.avro.Test.Builder clearMapVar() {
mapVar = null;
fieldSetFlags()[10] = false;
return this;
}
public com.yqu.avro.md5 getFixedVar() {
return fixedVar;
}
public com.yqu.avro.Test.Builder setFixedVar(com.yqu.avro.md5 value) {
validate(fields()[11], value);
this.fixedVar = value;
fieldSetFlags()[11] = true;
return this;
}
public boolean hasFixedVar() {
return fieldSetFlags()[11];
}
public com.yqu.avro.Test.Builder clearFixedVar() {
fixedVar = null;
fieldSetFlags()[11] = false;
return this;
}
@Override
public Test build() {
try {
Test record = new Test();
record.stringVar = fieldSetFlags()[0] ? this.stringVar : (;
record.bytesVar = fieldSetFlags()[1] ? this.bytesVar : (;
record.booleanVar = fieldSetFlags()[2] ? this.booleanVar : (;
record.intVar = fieldSetFlags()[3] ? this.intVar : (;
record.longVar = fieldSetFlags()[4] ? this.longVar : (;
record.floatVar = fieldSetFlags()[5] ? this.floatVar : (;
record.doubleVar = fieldSetFlags()[6] ? this.doubleVar : (;
record.enumVar = fieldSetFlags()[7] ? this.enumVar : (com.yqu.avro.Suit) defaultValue(fields()[7]);
record.strArrayVar = fieldSetFlags()[8] ? this.strArrayVar : (;
record.intArrayVar = fieldSetFlags()[9] ? this.intArrayVar : (;
record.mapVar = fieldSetFlags()[10] ? this.mapVar : (;
record.fixedVar = fieldSetFlags()[11] ? this.fixedVar : (com.yqu.avro.md5) defaultValue(fields()[11]);
return record;
} catch (Exception e) {
throw new org.apache.avro.AvroRuntimeException(e);
}
}
}
}
Suit.java
package com.yqu.avro;
@SuppressWarnings("all")
@org.apache.avro.specific.AvroGenerated
public enum Suit {
SPADES, HEARTS, DIAMONDS, CLUBS ;
public static final org.apache.avro.Schema SCHEMA$ =
new org.apache.avro.Schema.Parser().parse(
"{"type":"enum","name":"Suit","namespace":"com.yqu.avro","symbols":["SPADES","HEARTS","DIAMONDS","CLUBS"]}");
public static org.apache.avro.Schema getClassSchema() {
return SCHEMA$;
}
}
Md5.java
package com.yqu.avro;
@SuppressWarnings("all")
@org.apache.avro.specific.FixedSize(16)
@org.apache.avro.specific.AvroGenerated
public class Md5 extends org.apache.avro.specific.SpecificFixed {
public static final org.apache.avro.Schema SCHEMA$ =
new org.apache.avro.Schema.Parser().parse(
"{"type":"fixed","name":"Md5","namespace":"com.yqu.avro","size":16}");
public static org.apache.avro.Schema getClassSchema() { return SCHEMA$; }
public Md5() {
super();
}
public Md5(byte[] bytes) {
super(bytes);
}
}
参考：