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rx-java Observables for jdbc
package com.github.davidmoten.rx.jdbc;
import static com.github.davidmoten.rx.jdbc.Conditions.checkNotNull;
import static com.github.davidmoten.rx.jdbc.Queries.bufferedParameters;
import java.sql.ResultSet;
import java.util.List;
import rx.Observable;
import rx.Observable.Operator;
import rx.functions.Func1;
import com.github.davidmoten.rx.RxUtil;
import com.github.davidmoten.rx.jdbc.tuple.Tuple2;
import com.github.davidmoten.rx.jdbc.tuple.Tuple3;
import com.github.davidmoten.rx.jdbc.tuple.Tuple4;
import com.github.davidmoten.rx.jdbc.tuple.Tuple5;
import com.github.davidmoten.rx.jdbc.tuple.Tuple6;
import com.github.davidmoten.rx.jdbc.tuple.Tuple7;
import com.github.davidmoten.rx.jdbc.tuple.TupleN;
import com.github.davidmoten.rx.jdbc.tuple.Tuples;
/**
* A query and its executable context.
*/
final public class QuerySelect implements Query {
private final String sql;
private final Observable parameters;
private final QueryContext context;
private Observable depends = Observable.empty();
/**
* Constructor.
*
* @param sql
* @param parameters
* @param depends
* @param context
*/
private QuerySelect(String sql, Observable parameters,
Observable depends, QueryContext context) {
checkNotNull(sql);
checkNotNull(parameters);
checkNotNull(depends);
checkNotNull(context);
this.sql = sql;
this.parameters = parameters;
this.depends = depends;
this.context = context;
}
@Override
public String sql() {
return sql;
}
@Override
public QueryContext context() {
return context;
}
@Override
public Observable parameters() {
return parameters;
}
@Override
public String toString() {
return "QuerySelect [sql=" + sql + "]";
}
@Override
public Observable depends() {
return depends;
}
/**
* Returns the results of running a select query with all sets of
* parameters.
*
* @return
*/
public Observable execute(Func1 function) {
return bufferedParameters(this)
// execute once per set of parameters
.concatMap(executeOnce(function));
}
/**
* Returns a {@link Func1} that itself returns the results of pushing one
* set of parameters through a select query.
*
* @param query
* @return
*/
private Func1, Observable> executeOnce(
final Func1 function) {
return new Func1, Observable>() {
@Override
public Observable call(List params) {
return executeOnce(params, function);
}
};
}
/**
* Returns an Observable of the results of pushing one set of parameters
* through a select query.
*
* @param params
* one set of parameters to be run with the query
* @return
*/
private Observable executeOnce(final List params,
Func1 function) {
return QuerySelectOperation.execute(this, params, function)
.subscribeOn(context.scheduler());
}
/**
* Builds a {@link QuerySelect}.
*/
final public static class Builder {
/**
* Builds the standard stuff.
*/
private final QueryBuilder builder;
/**
* Constructor.
*
* @param sql
* @param db
*/
public Builder(String sql, Database db) {
builder = new QueryBuilder(sql, db);
}
/**
* Appends the given parameters to the parameter list for the query. If
* there are more parameters than required for one execution of the
* query then more than one execution of the query will occur.
*
* @param parameters
* @return this
*/
public Builder parameters(Observable parameters) {
builder.parameters(parameters);
return this;
}
/**
* Appends the given parameter values to the parameter list for the
* query. If there are more parameters than required for one execution
* of the query then more than one execution of the query will occur.
*
* @param objects
* @return this
*/
public Builder parameters(Object... objects) {
builder.parameters(objects);
return this;
}
/**
* Appends a parameter to the parameter list for the query. If there are
* more parameters than required for one execution of the query then
* more than one execution of the query will occur.
*
* @param value
* @return this
*/
public Builder parameter(Object value) {
builder.parameter(value);
return this;
}
/**
* Appends a dependency to the dependencies that have to complete their
* emitting before the query is executed.
*
* @param dependency
* @return this
*/
public Builder dependsOn(Observable dependency) {
builder.dependsOn(dependency);
return this;
}
/**
* Appends a dependency on the result of the last transaction (
* true for commit or false for rollback) to
* the dependencies that have to complete their emitting before the
* query is executed.
*
* @return this
*/
public Builder dependsOnLastTransaction() {
builder.dependsOnLastTransaction();
return this;
}
/**
* Transforms the results using the given function.
*
* @param function
* @return
*/
public Observable get(Func1 function) {
return new QuerySelect(builder.sql(), builder.parameters(),
builder.depends(), builder.context()).execute(function);
}
/**
*
* Transforms each row of the {@link ResultSet} into an instance of
* T using automapping of the ResultSet columns into
* corresponding constructor parameters that are assignable. Beyond
* normal assignable criteria (for example Integer 123 is assignable to
* a Double) other conversions exist to facilitate the automapping:
*
*
* They are:
*
* - java.sql.Blob ➟ byte[]
* - java.sql.Blob ➟ java.io.InputStream
* - java.sql.Clob ➟ String
* - java.sql.Clob ➟ java.io.Reader
* - java.sql.Date ➟ java.util.Date
* - java.sql.Date ➟ Long
* - java.sql.Timestamp ➟ java.util.Date
* - java.sql.Timestamp ➟ Long
* - java.sql.Time ➟ java.util.Date
* - java.sql.Time ➟ Long
* - java.math.BigInteger ➟
* Short,Integer,Long,Float,Double,BigDecimal
* - java.math.BigDecimal ➟
* Short,Integer,Long,Float,Double,BigInteger
*
*
* @param cls
* @return
*/
public Observable autoMap(Class cls) {
return get(Util.autoMap(cls));
}
/**
* Automaps the first column of the ResultSet into the target class
* cls.
*
* @param cls
* @return
*/
public Observable getAs(Class cls) {
return get(Tuples.single(cls));
}
/**
* Automaps all the columns of the {@link ResultSet} into the target
* class cls. See {@link #autoMap(Class) autoMap()}.
*
* @param cls
* @return
*/
public Observable> getTupleN(Class cls) {
return get(Tuples.tupleN(cls));
}
/**
* Automaps all the columns of the {@link ResultSet} into {@link Object}
* . See {@link #autoMap(Class) autoMap()}.
*
* @param cls
* @return
*/
public Observable> getTupleN() {
return get(Tuples.tupleN(Object.class));
}
/**
* Automaps the columns of the {@link ResultSet} into the specified
* classes. See {@link #autoMap(Class) autoMap()}.
*
* @param cls1
* @param cls2
* @return
*/
public Observable> getAs(Class cls1,
Class cls2) {
return get(Tuples.tuple(cls1, cls2));
}
/**
* Automaps the columns of the {@link ResultSet} into the specified
* classes. See {@link #autoMap(Class) autoMap()}.
*
* @param cls1
* @param cls2
* @param cls3
* @return
*/
public Observable> getAs(
Class cls1, Class cls2, Class cls3) {
return get(Tuples.tuple(cls1, cls2, cls3));
}
/**
* Automaps the columns of the {@link ResultSet} into the specified
* classes. See {@link #autoMap(Class) autoMap()}.
*
* @param cls1
* @param cls2
* @param cls3
* @param cls4
* @return
*/
public Observable> getAs(
Class cls1, Class cls2, Class cls3, Class cls4) {
return get(Tuples.tuple(cls1, cls2, cls3, cls4));
}
/**
* Automaps the columns of the {@link ResultSet} into the specified
* classes. See {@link #autoMap(Class) autoMap()}.
*
* @param cls1
* @param cls2
* @param cls3
* @param cls4
* @param cls5
* @return
*/
public Observable> getAs(
Class cls1, Class cls2, Class cls3, Class cls4,
Class cls5) {
return get(Tuples.tuple(cls1, cls2, cls3, cls4, cls5));
}
/**
* Automaps the columns of the {@link ResultSet} into the specified
* classes. See {@link #autoMap(Class) autoMap()}.
*
* @param cls1
* @param cls2
* @param cls3
* @param cls4
* @param cls5
* @param cls6
* @return
*/
public Observable> getAs(
Class cls1, Class cls2, Class cls3, Class cls4,
Class cls5, Class cls6) {
return get(Tuples.tuple(cls1, cls2, cls3, cls4, cls5, cls6));
}
/**
* Automaps the columns of the {@link ResultSet} into the specified
* classes. See {@link #autoMap(Class) autoMap()}.
*
* @param cls1
* @param cls2
* @param cls3
* @param cls4
* @param cls5
* @param cls6
* @param cls7
* @return
*/
public Observable> getAs(
Class cls1, Class cls2, Class cls3, Class cls4,
Class cls5, Class cls6, Class cls7) {
return get(Tuples.tuple(cls1, cls2, cls3, cls4, cls5, cls6, cls7));
}
public Observable count() {
return get(RxUtil. constant(1)).count();
}
/**
* Returns an {@link Operator} to allow the query to be pushed
* parameters via the {@link Observable#lift(Operator)} method.
*
* @return operator that acts on parameters
*/
public OperatorBuilder
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