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Merge pull request #281 from ankurkaushal/master

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Reformat according to google style guide
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Ilkka Seppälä
2015-11-02 21:39:17 +02:00
parent 7e4f04602e 306b1f3d31
commit fe63c9cec4
438 changed files with 8257 additions and 8382 deletions
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66
tolerant-reader/src/main/java/com/iluwatar/tolerantreader/App.java
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@ -4,39 +4,43 @@ import java.io.IOException;
/**
*
* Tolerant Reader is an integration pattern that helps creating robust communication
* systems. The idea is to be as tolerant as possible when reading data from another
* service. This way, when the communication schema changes, the readers must not break.
* Tolerant Reader is an integration pattern that helps creating robust communication systems. The
* idea is to be as tolerant as possible when reading data from another service. This way, when the
* communication schema changes, the readers must not break.
* <p>
* In this example we use Java serialization to write representations of {@link RainbowFish}
* objects to file. {@link RainbowFish} is the initial version which we can easily read and
* write using {@link RainbowFishSerializer} methods. {@link RainbowFish} then evolves to {@link RainbowFishV2}
* and we again write it to file with a method designed to do just that. However, the reader
* client does not know about the new format and still reads with the method designed for
* V1 schema. Fortunately the reading method has been designed with the Tolerant Reader
* pattern and does not break even though {@link RainbowFishV2} has new fields that are serialized.
* In this example we use Java serialization to write representations of {@link RainbowFish} objects
* to file. {@link RainbowFish} is the initial version which we can easily read and write using
* {@link RainbowFishSerializer} methods. {@link RainbowFish} then evolves to {@link RainbowFishV2}
* and we again write it to file with a method designed to do just that. However, the reader client
* does not know about the new format and still reads with the method designed for V1 schema.
* Fortunately the reading method has been designed with the Tolerant Reader pattern and does not
* break even though {@link RainbowFishV2} has new fields that are serialized.
*
*/
public class App {
public static void main( String[] args ) throws IOException, ClassNotFoundException {
// Write V1
RainbowFish fishV1 = new RainbowFish("Zed", 10, 11, 12);
System.out.println(String.format("fishV1 name=%s age=%d length=%d weight=%d", fishV1.getName(),
fishV1.getAge(), fishV1.getLengthMeters(), fishV1.getWeightTons()));
RainbowFishSerializer.writeV1(fishV1, "fish1.out");
// Read V1
RainbowFish deserializedFishV1 = RainbowFishSerializer.readV1("fish1.out");
System.out.println(String.format("deserializedFishV1 name=%s age=%d length=%d weight=%d", deserializedFishV1.getName(),
deserializedFishV1.getAge(), deserializedFishV1.getLengthMeters(), deserializedFishV1.getWeightTons()));
// Write V2
RainbowFishV2 fishV2 = new RainbowFishV2("Scar", 5, 12, 15, true, true, true);
System.out.println(String.format("fishV2 name=%s age=%d length=%d weight=%d sleeping=%b hungry=%b angry=%b", fishV2.getName(),
fishV2.getAge(), fishV2.getLengthMeters(), fishV2.getWeightTons(), fishV2.getHungry(), fishV2.getAngry(), fishV2.getSleeping()));
RainbowFishSerializer.writeV2(fishV2, "fish2.out");
// Read V2 with V1 method
RainbowFish deserializedFishV2 = RainbowFishSerializer.readV1("fish2.out");
System.out.println(String.format("deserializedFishV2 name=%s age=%d length=%d weight=%d", deserializedFishV2.getName(),
deserializedFishV2.getAge(), deserializedFishV2.getLengthMeters(), deserializedFishV2.getWeightTons()));
}
public static void main(String[] args) throws IOException, ClassNotFoundException {
// Write V1
RainbowFish fishV1 = new RainbowFish("Zed", 10, 11, 12);
System.out.println(String.format("fishV1 name=%s age=%d length=%d weight=%d", fishV1.getName(),
fishV1.getAge(), fishV1.getLengthMeters(), fishV1.getWeightTons()));
RainbowFishSerializer.writeV1(fishV1, "fish1.out");
// Read V1
RainbowFish deserializedFishV1 = RainbowFishSerializer.readV1("fish1.out");
System.out.println(String.format("deserializedFishV1 name=%s age=%d length=%d weight=%d",
deserializedFishV1.getName(), deserializedFishV1.getAge(),
deserializedFishV1.getLengthMeters(), deserializedFishV1.getWeightTons()));
// Write V2
RainbowFishV2 fishV2 = new RainbowFishV2("Scar", 5, 12, 15, true, true, true);
System.out.println(String.format(
"fishV2 name=%s age=%d length=%d weight=%d sleeping=%b hungry=%b angry=%b",
fishV2.getName(), fishV2.getAge(), fishV2.getLengthMeters(), fishV2.getWeightTons(),
fishV2.getHungry(), fishV2.getAngry(), fishV2.getSleeping()));
RainbowFishSerializer.writeV2(fishV2, "fish2.out");
// Read V2 with V1 method
RainbowFish deserializedFishV2 = RainbowFishSerializer.readV1("fish2.out");
System.out.println(String.format("deserializedFishV2 name=%s age=%d length=%d weight=%d",
deserializedFishV2.getName(), deserializedFishV2.getAge(),
deserializedFishV2.getLengthMeters(), deserializedFishV2.getWeightTons()));
}
}

52
tolerant-reader/src/main/java/com/iluwatar/tolerantreader/RainbowFish.java
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@ -9,34 +9,34 @@ import java.io.Serializable;
*/
public class RainbowFish implements Serializable {
private static final long serialVersionUID = 1L;
private String name;
private int age;
private int lengthMeters;
private int weightTons;
public RainbowFish(String name, int age, int lengthMeters, int weightTons) {
this.name = name;
this.age = age;
this.lengthMeters = lengthMeters;
this.weightTons = weightTons;
}
public String getName() {
return name;
}
private static final long serialVersionUID = 1L;
public int getAge() {
return age;
}
private String name;
private int age;
private int lengthMeters;
private int weightTons;
public int getLengthMeters() {
return lengthMeters;
}
public RainbowFish(String name, int age, int lengthMeters, int weightTons) {
this.name = name;
this.age = age;
this.lengthMeters = lengthMeters;
this.weightTons = weightTons;
}
public int getWeightTons() {
return weightTons;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
public int getLengthMeters() {
return lengthMeters;
}
public int getWeightTons() {
return weightTons;
}
}

126
tolerant-reader/src/main/java/com/iluwatar/tolerantreader/RainbowFishSerializer.java
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@ -10,71 +10,73 @@ import java.util.Map;
/**
*
* RainbowFishSerializer provides methods for reading and writing {@link RainbowFish} objects to file.
* Tolerant Reader pattern is implemented here by serializing maps instead of {@link RainbowFish} objects.
* This way the reader does not break even though new properties are added to the schema.
* RainbowFishSerializer provides methods for reading and writing {@link RainbowFish} objects to
* file. Tolerant Reader pattern is implemented here by serializing maps instead of
* {@link RainbowFish} objects. This way the reader does not break even though new properties are
* added to the schema.
*
*/
public class RainbowFishSerializer {
/**
* Write V1 RainbowFish to file
* @param rainbowFish
* @param filename
* @throws IOException
*/
public static void writeV1(RainbowFish rainbowFish, String filename) throws IOException {
Map<String, String> map = new HashMap<>();
map.put("name", rainbowFish.getName());
map.put("age", String.format("%d", rainbowFish.getAge()));
map.put("lengthMeters", String.format("%d", rainbowFish.getLengthMeters()));
map.put("weightTons", String.format("%d", rainbowFish.getWeightTons()));
FileOutputStream fileOut = new FileOutputStream(filename);
ObjectOutputStream objOut = new ObjectOutputStream(fileOut);
objOut.writeObject(map);
objOut.close();
fileOut.close();
}
/**
* Write V1 RainbowFish to file
*
* @param rainbowFish
* @param filename
* @throws IOException
*/
public static void writeV1(RainbowFish rainbowFish, String filename) throws IOException {
Map<String, String> map = new HashMap<>();
map.put("name", rainbowFish.getName());
map.put("age", String.format("%d", rainbowFish.getAge()));
map.put("lengthMeters", String.format("%d", rainbowFish.getLengthMeters()));
map.put("weightTons", String.format("%d", rainbowFish.getWeightTons()));
FileOutputStream fileOut = new FileOutputStream(filename);
ObjectOutputStream objOut = new ObjectOutputStream(fileOut);
objOut.writeObject(map);
objOut.close();
fileOut.close();
}
/**
* Write V2 RainbowFish to file
* @param rainbowFish
* @param filename
* @throws IOException
*/
public static void writeV2(RainbowFishV2 rainbowFish, String filename) throws IOException {
Map<String, String> map = new HashMap<>();
map.put("name", rainbowFish.getName());
map.put("age", String.format("%d", rainbowFish.getAge()));
map.put("lengthMeters", String.format("%d", rainbowFish.getLengthMeters()));
map.put("weightTons", String.format("%d", rainbowFish.getWeightTons()));
map.put("angry", Boolean.toString(rainbowFish.getAngry()));
map.put("hungry", Boolean.toString(rainbowFish.getHungry()));
map.put("sleeping", Boolean.toString(rainbowFish.getSleeping()));
FileOutputStream fileOut = new FileOutputStream(filename);
ObjectOutputStream objOut = new ObjectOutputStream(fileOut);
objOut.writeObject(map);
objOut.close();
fileOut.close();
}
/**
* Read V1 RainbowFish from file
* @param filename
* @return
* @throws IOException
* @throws ClassNotFoundException
*/
public static RainbowFish readV1(String filename) throws IOException, ClassNotFoundException {
Map<String, String> map = null;
FileInputStream fileIn = new FileInputStream(filename);
ObjectInputStream objIn = new ObjectInputStream(fileIn);
map = (Map<String, String>) objIn.readObject();
objIn.close();
fileIn.close();
return new RainbowFish(map.get("name"),
Integer.parseInt(map.get("age")),
Integer.parseInt(map.get("lengthMeters")),
Integer.parseInt(map.get("weightTons")));
}
/**
* Write V2 RainbowFish to file
*
* @param rainbowFish
* @param filename
* @throws IOException
*/
public static void writeV2(RainbowFishV2 rainbowFish, String filename) throws IOException {
Map<String, String> map = new HashMap<>();
map.put("name", rainbowFish.getName());
map.put("age", String.format("%d", rainbowFish.getAge()));
map.put("lengthMeters", String.format("%d", rainbowFish.getLengthMeters()));
map.put("weightTons", String.format("%d", rainbowFish.getWeightTons()));
map.put("angry", Boolean.toString(rainbowFish.getAngry()));
map.put("hungry", Boolean.toString(rainbowFish.getHungry()));
map.put("sleeping", Boolean.toString(rainbowFish.getSleeping()));
FileOutputStream fileOut = new FileOutputStream(filename);
ObjectOutputStream objOut = new ObjectOutputStream(fileOut);
objOut.writeObject(map);
objOut.close();
fileOut.close();
}
/**
* Read V1 RainbowFish from file
*
* @param filename
* @return
* @throws IOException
* @throws ClassNotFoundException
*/
public static RainbowFish readV1(String filename) throws IOException, ClassNotFoundException {
Map<String, String> map = null;
FileInputStream fileIn = new FileInputStream(filename);
ObjectInputStream objIn = new ObjectInputStream(fileIn);
map = (Map<String, String>) objIn.readObject();
objIn.close();
fileIn.close();
return new RainbowFish(map.get("name"), Integer.parseInt(map.get("age")), Integer.parseInt(map
.get("lengthMeters")), Integer.parseInt(map.get("weightTons")));
}
}

55
tolerant-reader/src/main/java/com/iluwatar/tolerantreader/RainbowFishV2.java
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@ -7,32 +7,33 @@ package com.iluwatar.tolerantreader;
*/
public class RainbowFishV2 extends RainbowFish {
private static final long serialVersionUID = 1L;
private boolean sleeping;
private boolean hungry;
private boolean angry;
private static final long serialVersionUID = 1L;
public RainbowFishV2(String name, int age, int lengthMeters, int weightTons) {
super(name, age, lengthMeters, weightTons);
}
public RainbowFishV2(String name, int age, int lengthMeters, int weightTons, boolean sleeping, boolean hungry, boolean angry) {
this(name, age, lengthMeters, weightTons);
this.sleeping = sleeping;
this.hungry = hungry;
this.angry = angry;
}
public boolean getSleeping() {
return sleeping;
}
public boolean getHungry() {
return hungry;
}
public boolean getAngry() {
return angry;
}
private boolean sleeping;
private boolean hungry;
private boolean angry;
public RainbowFishV2(String name, int age, int lengthMeters, int weightTons) {
super(name, age, lengthMeters, weightTons);
}
public RainbowFishV2(String name, int age, int lengthMeters, int weightTons, boolean sleeping,
boolean hungry, boolean angry) {
this(name, age, lengthMeters, weightTons);
this.sleeping = sleeping;
this.hungry = hungry;
this.angry = angry;
}
public boolean getSleeping() {
return sleeping;
}
public boolean getHungry() {
return hungry;
}
public boolean getAngry() {
return angry;
}
}

30
tolerant-reader/src/test/java/com/iluwatar/tolerantreader/AppTest.java
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@ -15,19 +15,19 @@ import com.iluwatar.tolerantreader.App;
*
*/
public class AppTest {
@Test
public void test() throws ClassNotFoundException, IOException {
String[] args = {};
App.main(args);
}
@Before
@After
public void cleanup() {
File file1 = new File("fish1.out");
file1.delete();
File file2 = new File("fish2.out");
file2.delete();
}
@Test
public void test() throws ClassNotFoundException, IOException {
String[] args = {};
App.main(args);
}
@Before
@After
public void cleanup() {
File file1 = new File("fish1.out");
file1.delete();
File file2 = new File("fish2.out");
file2.delete();
}
}