From d7249ab93dad3ba9be0389f402c1378d7f1eb5ad Mon Sep 17 00:00:00 2001 From: sowgro Date: Thu, 2 Oct 2025 22:09:13 -0400 Subject: Implement basic serialization --- .../design/persistence/JSONPersonalDatabase.java | 65 ++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 src/main/java/design/persistence/JSONPersonalDatabase.java (limited to 'src/main/java/design/persistence/JSONPersonalDatabase.java') diff --git a/src/main/java/design/persistence/JSONPersonalDatabase.java b/src/main/java/design/persistence/JSONPersonalDatabase.java new file mode 100644 index 0000000..3ec0012 --- /dev/null +++ b/src/main/java/design/persistence/JSONPersonalDatabase.java @@ -0,0 +1,65 @@ +package design.persistence; + +import com.fasterxml.jackson.databind.ObjectMapper; +import design.model.Golfer; + +import java.io.File; +import java.io.IOException; +import java.util.HashMap; +import java.util.Map; + +public class JSONPersonalDatabase implements PersonalDatabase { + + private final Map cache; + private final ObjectMapper mapper; + private final File file; + + public JSONPersonalDatabase(String filename) throws IOException { + this.file = new File(filename); + this.cache = new HashMap<>(); + this.mapper = new ObjectMapper(); + + load(); + } + + private void load() throws IOException { + Golfer[] data = mapper.readValue(file, Golfer[].class); + cache.clear(); + for (Golfer i : data) { + cache.put(i.getUsername(), i); + } + } + + private void save() throws IOException { + Golfer[] data = cache.values().toArray(Golfer[]::new); + mapper.writeValue(file, data); + } + + @Override + public Golfer[] getGolfers() { + return new Golfer[0]; + } + + @Override + public Golfer getGolfer(String username) { + return cache.get(username); + } + + @Override + public void addGolfer(Golfer golfer) throws IOException { + cache.put(golfer.getUsername(), golfer); + save(); + } + + @Override + public void removeGolfer(Golfer golfer) throws IOException { + cache.remove(golfer.getUsername()); + save(); + } + + @Override + public void updateGolfer(Golfer golfer) throws IOException { + cache.put(golfer.getUsername(), golfer); + save(); + } +} -- cgit v1.2.3 From d982cfe8a22ec7eb89186fed875a483a51c3505f Mon Sep 17 00:00:00 2001 From: sowgro Date: Fri, 3 Oct 2025 00:31:02 -0400 Subject: Add code to handle id serialization --- .../design/persistence/JSONPersonalDatabase.java | 40 ++++++++++++++++++++-- 1 file changed, 37 insertions(+), 3 deletions(-) (limited to 'src/main/java/design/persistence/JSONPersonalDatabase.java') diff --git a/src/main/java/design/persistence/JSONPersonalDatabase.java b/src/main/java/design/persistence/JSONPersonalDatabase.java index 3ec0012..511d962 100644 --- a/src/main/java/design/persistence/JSONPersonalDatabase.java +++ b/src/main/java/design/persistence/JSONPersonalDatabase.java @@ -1,6 +1,12 @@ package design.persistence; -import com.fasterxml.jackson.databind.ObjectMapper; +import com.fasterxml.jackson.annotation.JsonAutoDetect; +import com.fasterxml.jackson.annotation.PropertyAccessor; +import com.fasterxml.jackson.core.JsonGenerator; +import com.fasterxml.jackson.core.JsonParser; +import com.fasterxml.jackson.databind.*; +import com.fasterxml.jackson.databind.module.SimpleModule; +import design.model.Course; import design.model.Golfer; import java.io.File; @@ -14,12 +20,23 @@ public class JSONPersonalDatabase implements PersonalDatabase { private final ObjectMapper mapper; private final File file; - public JSONPersonalDatabase(String filename) throws IOException { + public JSONPersonalDatabase(String filename) { this.file = new File(filename); this.cache = new HashMap<>(); this.mapper = new ObjectMapper(); - load(); + SimpleModule module = new SimpleModule(); + module.addDeserializer(Course.class, new CourseIdDeserializer()); + module.addSerializer(Course.class, new CourseIdSerializer()); + mapper.registerModule(module); + mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY); + mapper.writerWithDefaultPrettyPrinter(); + + try { + load(); + } catch (IOException ex) { + throw new RuntimeException(ex); + } } private void load() throws IOException { @@ -62,4 +79,21 @@ public class JSONPersonalDatabase implements PersonalDatabase { cache.put(golfer.getUsername(), golfer); save(); } + + private static class CourseIdSerializer extends JsonSerializer { + @Override + public void serialize(Course course, JsonGenerator gen, SerializerProvider serializers) throws IOException { + gen.writeNumber(course.getId()); + } + } + + private static class CourseIdDeserializer extends JsonDeserializer { + MasterDatabase masterDB = MasterDatabase.INSTANCE; + + @Override + public Course deserialize(JsonParser p, DeserializationContext context) throws IOException { + int id = p.getValueAsInt(); + return masterDB.getCourse(id); + } + } } -- cgit v1.2.3 From 29c4a7caffea3957b8ac5f6be13d640c1a798989 Mon Sep 17 00:00:00 2001 From: sowgro Date: Fri, 3 Oct 2025 20:37:43 -0400 Subject: Serialization fully working --- src/main/java/design/persistence/JSONPersonalDatabase.java | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'src/main/java/design/persistence/JSONPersonalDatabase.java') diff --git a/src/main/java/design/persistence/JSONPersonalDatabase.java b/src/main/java/design/persistence/JSONPersonalDatabase.java index 511d962..dd63407 100644 --- a/src/main/java/design/persistence/JSONPersonalDatabase.java +++ b/src/main/java/design/persistence/JSONPersonalDatabase.java @@ -1,11 +1,13 @@ package design.persistence; import com.fasterxml.jackson.annotation.JsonAutoDetect; +import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParser; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.databind.module.SimpleModule; +import com.fasterxml.jackson.module.paramnames.ParameterNamesModule; import design.model.Course; import design.model.Golfer; @@ -30,7 +32,7 @@ public class JSONPersonalDatabase implements PersonalDatabase { module.addSerializer(Course.class, new CourseIdSerializer()); mapper.registerModule(module); mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY); - mapper.writerWithDefaultPrettyPrinter(); + mapper.registerModule(new ParameterNamesModule(JsonCreator.Mode.PROPERTIES)); try { load(); @@ -49,7 +51,7 @@ public class JSONPersonalDatabase implements PersonalDatabase { private void save() throws IOException { Golfer[] data = cache.values().toArray(Golfer[]::new); - mapper.writeValue(file, data); + mapper.writerWithDefaultPrettyPrinter().writeValue(file, data); } @Override -- cgit v1.2.3 From 0d9775a779f656ab55a22e5df5f6f83f7069fa95 Mon Sep 17 00:00:00 2001 From: sowgro Date: Fri, 3 Oct 2025 21:40:23 -0400 Subject: tweak pretty print and datetime serialization --- .../java/design/persistence/JSONPersonalDatabase.java | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'src/main/java/design/persistence/JSONPersonalDatabase.java') diff --git a/src/main/java/design/persistence/JSONPersonalDatabase.java b/src/main/java/design/persistence/JSONPersonalDatabase.java index dd63407..0efa362 100644 --- a/src/main/java/design/persistence/JSONPersonalDatabase.java +++ b/src/main/java/design/persistence/JSONPersonalDatabase.java @@ -5,8 +5,11 @@ import com.fasterxml.jackson.annotation.JsonCreator; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParser; +import com.fasterxml.jackson.core.util.DefaultIndenter; +import com.fasterxml.jackson.core.util.DefaultPrettyPrinter; import com.fasterxml.jackson.databind.*; import com.fasterxml.jackson.databind.module.SimpleModule; +import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule; import com.fasterxml.jackson.module.paramnames.ParameterNamesModule; import design.model.Course; import design.model.Golfer; @@ -33,6 +36,7 @@ public class JSONPersonalDatabase implements PersonalDatabase { mapper.registerModule(module); mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY); mapper.registerModule(new ParameterNamesModule(JsonCreator.Mode.PROPERTIES)); + mapper.registerModule(new JavaTimeModule()); try { load(); @@ -51,7 +55,7 @@ public class JSONPersonalDatabase implements PersonalDatabase { private void save() throws IOException { Golfer[] data = cache.values().toArray(Golfer[]::new); - mapper.writerWithDefaultPrettyPrinter().writeValue(file, data); + mapper.writer(new CustomPrettyPrinter()).writeValue(file, data); } @Override @@ -98,4 +102,17 @@ public class JSONPersonalDatabase implements PersonalDatabase { return masterDB.getCourse(id); } } + + private static class CustomPrettyPrinter extends DefaultPrettyPrinter { + public CustomPrettyPrinter() { + super._arrayIndenter = new DefaultIndenter(); + super._objectFieldValueSeparatorWithSpaces = _separators.getObjectFieldValueSeparator() + " "; + super._arrayEmptySeparator = ""; + } + + @Override + public CustomPrettyPrinter createInstance() { + return new CustomPrettyPrinter(); + } + } } -- cgit v1.2.3