Replace Guava Optional to java.util.Optional

Along with it, it upgrades embulk-util-aws-credentials for embulk-output-redshift
so that it uses java.util.Optional.

Author: Dai MIKURUBE

embulk-output-db2/src/main/java/org/embulk/output/DB2OutputPlugin.java

@@ -3,6 +3,7 @@
 import java.io.IOException;
 import java.sql.SQLException;
 import java.util.Properties;
+import java.util.Optional;
 
 import org.embulk.config.Config;
 import org.embulk.config.ConfigDefault;
@@ -13,7 +14,6 @@
 import org.embulk.output.jdbc.BatchInsert;
 import org.embulk.output.jdbc.MergeConfig;
 
-import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableSet;
 import static java.util.Locale.ENGLISH;
 

embulk-output-db2/src/main/java/org/embulk/output/db2/DB2BatchInsert.java

@@ -2,13 +2,12 @@
 
 import java.io.IOException;
 import java.sql.SQLException;
+import java.util.Optional;
 
 import org.embulk.output.jdbc.JdbcOutputConnector;
 import org.embulk.output.jdbc.MergeConfig;
 import org.embulk.output.jdbc.StandardBatchInsert;
 
-import com.google.common.base.Optional;
-
 public class DB2BatchInsert
         extends StandardBatchInsert
 {

embulk-output-db2/src/main/java/org/embulk/output/db2/DB2OutputConnector.java

@@ -3,14 +3,13 @@
 import java.sql.Connection;
 import java.sql.DriverManager;
 import java.sql.SQLException;
+import java.util.Optional;
 import java.util.Properties;
 
 import org.embulk.output.jdbc.JdbcOutputConnection;
 import org.embulk.output.jdbc.AbstractJdbcOutputConnector;
 import org.embulk.output.jdbc.TransactionIsolation;
 
-import com.google.common.base.Optional;
-
 public class DB2OutputConnector
         extends AbstractJdbcOutputConnector
 {

embulk-output-jdbc/src/main/java/org/embulk/output/JdbcOutputPlugin.java

@@ -5,8 +5,8 @@
 import java.io.IOException;
 import java.sql.Connection;
 import java.sql.SQLException;
+import java.util.Optional;
 
-import com.google.common.base.Optional;
 import com.google.common.base.Throwables;
 import com.google.common.collect.ImmutableSet;
 
@@ -83,7 +83,7 @@ protected GenericOutputConnector getConnector(PluginTask task, boolean retryable
         logConnectionProperties(t.getUrl(), props);
 
         return new GenericOutputConnector(t.getUrl(), props, t.getDriverClass(),
-                t.getSchema().orNull());
+                t.getSchema().orElse(null));
     }
 
     private static class GenericOutputConnector

embulk-output-jdbc/src/main/java/org/embulk/output/jdbc/AbstractJdbcOutputConnector.java

@@ -1,8 +1,7 @@
 package org.embulk.output.jdbc;
 
 import java.sql.SQLException;
-
-import com.google.common.base.Optional;
+import java.util.Optional;
 
 public abstract class AbstractJdbcOutputConnector implements JdbcOutputConnector
 {

embulk-output-jdbc/src/main/java/org/embulk/output/jdbc/AbstractJdbcOutputPlugin.java

@@ -21,6 +21,8 @@
 import java.sql.ResultSet;
 import java.sql.DatabaseMetaData;
 import java.sql.SQLException;
+import java.util.Optional;
+import java.util.function.Supplier;
 
 import org.embulk.spi.util.RetryExecutor;
 import org.embulk.spi.util.RetryExecutor.RetryGiveupException;
@@ -31,9 +33,7 @@
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonValue;
 import com.fasterxml.jackson.annotation.JsonProperty;
-import com.google.common.base.Optional;
 import com.google.common.base.Function;
-import com.google.common.base.Supplier;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
 import com.google.common.collect.ImmutableList;
@@ -549,12 +549,12 @@ protected void doBegin(JdbcOutputConnection con,
 
         Optional<JdbcSchema> initialTargetTableSchema =
             mode.ignoreTargetTableSchema() ?
-                Optional.<JdbcSchema>absent() :
+                Optional.<JdbcSchema>empty() :
                 newJdbcSchemaFromTableIfExists(con, task.getActualTable());
 
         // TODO get CREATE TABLE statement from task if set
         JdbcSchema newTableSchema = applyColumnOptionsToNewTableSchema(
-                initialTargetTableSchema.or(new Supplier<JdbcSchema>() {
+                initialTargetTableSchema.orElseGet(new Supplier<JdbcSchema>() {
                     public JdbcSchema get()
                     {
                         return newJdbcSchemaForNewTable(schema);
@@ -568,7 +568,7 @@ public JdbcSchema get()
             task.setIntermediateTables(Optional.<List<TableIdentifier>>of(createIntermediateTables(con, task, taskCount, newTableSchema)));
         } else {
             // direct modify mode doesn't need intermediate tables.
-            task.setIntermediateTables(Optional.<List<TableIdentifier>>absent());
+            task.setIntermediateTables(Optional.<List<TableIdentifier>>empty());
             if (task.getBeforeLoad().isPresent()) {
                 con.executeSql(task.getBeforeLoad().get());
             }
@@ -578,7 +578,7 @@ public JdbcSchema get()
         JdbcSchema targetTableSchema;
         if (initialTargetTableSchema.isPresent()) {
             targetTableSchema = initialTargetTableSchema.get();
-            task.setNewTableSchema(Optional.<JdbcSchema>absent());
+            task.setNewTableSchema(Optional.<JdbcSchema>empty());
         } else if (task.getIntermediateTables().isPresent() && !task.getIntermediateTables().get().isEmpty()) {
             TableIdentifier firstItermTable = task.getIntermediateTables().get().get(0);
             targetTableSchema = newJdbcSchemaFromTableIfExists(con, firstItermTable).get();
@@ -588,7 +588,7 @@ public JdbcSchema get()
             // CREATE TABLE IF NOT EXISTS xyz
             con.createTableIfNotExists(task.getActualTable(), newTableSchema, task.getCreateTableConstraint(), task.getCreateTableOption());
             targetTableSchema = newJdbcSchemaFromTableIfExists(con, task.getActualTable()).get();
-            task.setNewTableSchema(Optional.<JdbcSchema>absent());
+            task.setNewTableSchema(Optional.<JdbcSchema>empty());
         }
         task.setTargetTableSchema(matchSchemaByColumnNames(schema, targetTableSchema));
 
@@ -629,7 +629,7 @@ public JdbcSchema get()
             }
             logger.info("Using merge keys: {}", task.getMergeKeys().get());
         } else {
-            task.setMergeKeys(Optional.<List<String>>absent());
+            task.setMergeKeys(Optional.<List<String>>empty());
         }
     }
 
@@ -793,7 +793,7 @@ protected static List<ColumnSetter> newColumnSetters(ColumnSetterFactory factory
 
     private static JdbcColumnOption columnOptionOf(Map<String, JdbcColumnOption> columnOptions, String columnName)
     {
-        return Optional.fromNullable(columnOptions.get(columnName)).or(
+        return Optional.ofNullable(columnOptions.get(columnName)).orElseGet(
                     // default column option
                     new Supplier<JdbcColumnOption>()
                     {
@@ -927,7 +927,7 @@ public Optional<JdbcSchema> newJdbcSchemaFromTableIfExists(JdbcOutputConnection
     {
         if (!connection.tableExists(table)) {
             // DatabaseMetaData.getPrimaryKeys fails if table does not exist
-            return Optional.absent();
+            return Optional.empty();
         }
 
         DatabaseMetaData dbm = connection.getMetaData();
@@ -974,7 +974,7 @@ public Optional<JdbcSchema> newJdbcSchemaFromTableIfExists(JdbcOutputConnection
         }
         List<JdbcColumn> columns = builder.build();
         if (columns.isEmpty()) {
-            return Optional.absent();
+            return Optional.empty();
         } else {
             return Optional.of(new JdbcSchema(columns));
         }
@@ -986,7 +986,7 @@ private JdbcSchema matchSchemaByColumnNames(Schema inputSchema, JdbcSchema targe
 
         for (Column column : inputSchema.getColumns()) {
             Optional<JdbcColumn> c = targetTableSchema.findColumn(column.getName());
-            jdbcColumns.add(c.or(JdbcColumn.skipColumn()));
+            jdbcColumns.add(c.orElse(JdbcColumn.skipColumn()));
         }
 
         return new JdbcSchema(jdbcColumns.build());
@@ -1000,7 +1000,7 @@ public TransactionalPageOutput open(TaskSource taskSource, Schema schema, final
         // instantiate BatchInsert without table name
         BatchInsert batch = null;
         try {
-            Optional<MergeConfig> config = Optional.absent();
+            Optional<MergeConfig> config = Optional.empty();
             if (task.getMode() == Mode.MERGE_DIRECT) {
                 config = Optional.of(new MergeConfig(task.getMergeKeys().get(), task.getMergeRule()));
             }

embulk-output-jdbc/src/main/java/org/embulk/output/jdbc/JdbcColumn.java

@@ -1,9 +1,9 @@
 package org.embulk.output.jdbc;
 
-import com.google.common.base.Optional;
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import java.util.Optional;
 
 public class JdbcColumn
 {
@@ -46,7 +46,7 @@ public static JdbcColumn newGenericTypeColumn(String name, int sqlType,
     {
         return new JdbcColumn(name, sqlType,
                 simpleTypeName, sizeTypeParameter, scaleTypeParameter, dataLength,
-                Optional.<String>absent(), isNotNull, isUniqueKey);
+                Optional.<String>empty(), isNotNull, isUniqueKey);
     }
 
     public static JdbcColumn newGenericTypeColumn(String name, int sqlType,
@@ -55,7 +55,7 @@ public static JdbcColumn newGenericTypeColumn(String name, int sqlType,
     {
         return new JdbcColumn(name, sqlType,
                 simpleTypeName, sizeTypeParameter, scaleTypeParameter, sizeTypeParameter,
-                Optional.<String>absent(), isNotNull, isUniqueKey);
+                Optional.<String>empty(), isNotNull, isUniqueKey);
     }
 
     public static JdbcColumn newTypeDeclaredColumn(String name, int sqlType,
@@ -69,7 +69,7 @@ public static JdbcColumn newTypeDeclaredColumn(String name, int sqlType,
     @JsonIgnore
     public static JdbcColumn skipColumn()
     {
-        return new JdbcColumn(null, 0, null, 0, 0, 0, Optional.<String>absent(), false, false);
+        return new JdbcColumn(null, 0, null, 0, 0, 0, Optional.<String>empty(), false, false);
     }
 
     @JsonIgnore

embulk-output-jdbc/src/main/java/org/embulk/output/jdbc/JdbcColumnOption.java

@@ -1,6 +1,6 @@
 package org.embulk.output.jdbc;
 
-import com.google.common.base.Optional;
+import java.util.Optional;
 import org.joda.time.DateTimeZone;
 import org.embulk.config.Task;
 import org.embulk.config.Config;

embulk-output-jdbc/src/main/java/org/embulk/output/jdbc/JdbcOutputConnection.java

@@ -10,12 +10,11 @@
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.Locale;
+import java.util.Optional;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.common.base.Optional;
-
 public class JdbcOutputConnection
         implements AutoCloseable
 {

embulk-output-jdbc/src/main/java/org/embulk/output/jdbc/JdbcSchema.java

@@ -1,10 +1,10 @@
 package org.embulk.output.jdbc;
 
 import java.util.List;
+import java.util.Optional;
 
 import org.embulk.config.ConfigException;
 
-import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonValue;
@@ -48,7 +48,7 @@ public Optional<JdbcColumn> findColumn(String name)
         if (foundColumn != null) {
             return Optional.of(foundColumn);
         }
-        return Optional.absent();
+        return Optional.empty();
     }
 
     public int getCount()