com.quinsoft.zeidon.utils.QualificationBuilderFromJson Maven / Gradle / Ivy
/**
*
*/
package com.quinsoft.zeidon.utils;
import java.io.IOException;
import org.apache.commons.io.IOUtils;
import org.apache.commons.lang3.StringUtils;
import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonLocation;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonToken;
import com.quinsoft.zeidon.Pagination;
import com.quinsoft.zeidon.ZeidonException;
import com.quinsoft.zeidon.objectdefinition.AttributeDef;
import com.quinsoft.zeidon.objectdefinition.EntityDef;
/**
* Updates a QualifcationBuilder from a JSON string.
*
*/
public class QualificationBuilderFromJson
{
private final QualificationBuilder qualBuilder;
private JsonParser jp;
/**
*
*/
public QualificationBuilderFromJson( QualificationBuilder qb )
{
this.qualBuilder = qb;
}
/**
*
{
status: "A",
$or: [ { age: { $lt: 30 } }, { type: 1 } ]
$orderBy: [ { age: desc } ]
}
*/
public void parseJson( String json )
{
try
{
JsonFactory jsonFactory = new JsonFactory();
jp = jsonFactory.createParser( json );
jp.configure( JsonParser.Feature.AUTO_CLOSE_SOURCE, false );
EntityDef rootEntity = qualBuilder.getLodDef().getRoot();
jp.nextToken(); // Read the first token to get us started.
parseEntity( rootEntity, rootEntity );
}
catch ( Exception e )
{
qualBuilder.getTask().log().error( "JSON = \n%s", json );
ZeidonException ze = ZeidonException.wrapException( e );
JsonLocation loc = jp.getCurrentLocation();
JsonToken token = jp.getCurrentToken();
ze.appendMessage( "Position line=%d col=%d, token=%s", loc.getLineNr(), loc.getColumnNr(),
token == null ? "No Token" : token.name() );
throw ze;
}
finally
{
if ( jp != null )
{
IOUtils.closeQuietly( jp );
jp = null;
}
}
}
/**
*
* @param qualEntityDef - Entity we are qualifying on (e.g. restricting)
* @param entityDef - Entity of value.
*
* Often these are the same but they could be different, such as when qualifying
* an entity using a value from a child entity.
*
*/
private JsonToken parseEntity( EntityDef qualEntityDef, EntityDef entityDef ) throws JsonParseException, IOException
{
// Read the START_OBJECT
JsonToken token = jp.getCurrentToken();
if ( token != JsonToken.START_OBJECT )
throw new ZeidonException( "JSON doesn't start with object. Found %s", token );
boolean first = true;
token = jp.nextToken(); // Consume '{'
while ( ( token = jp.getCurrentToken() ) != JsonToken.END_OBJECT )
{
if ( token != JsonToken.FIELD_NAME )
throw new ZeidonException( "Unexpected token; expecting FIELD" );
String fieldName = jp.getCurrentName();
// Some keywords don't immediately add qualattribs; we have to treat them
// differently because they don't add an "AND" oper. First make sure it's
// not an entity/attribute name.
AttributeDef attributeDef = entityDef.getAttribute( fieldName, false );
EntityDef childEntityDef = qualBuilder.getLodDef().getEntityDef( fieldName, false );
if ( attributeDef == null && childEntityDef == null )
{
switch ( fieldName.toLowerCase().trim() )
{
case "$restricting":
case "restricting":
case "$restrict":
case "restrict":
parseRestricting();
continue;
case "$rootonly":
case "rootonly":
case "$root_only":
case "root_only":
if ( parseBoolean( "rootOnly" ) )
qualBuilder.rootOnlyMultiple();
continue;
case "$readonly":
case "readonly":
case "$read_only":
case "read_only":
if ( parseBoolean( "readOnly" ) )
qualBuilder.readOnly();
continue;
case "$pagination":
case "pagination":
parsePagination();
continue;
case "$orderby":
case "orderby":
parseOrderBy( qualEntityDef );
continue;
case "$sql":
case "sql":
case "$usingsql":
case "usingsql":
parseOpenSql( fieldName, qualEntityDef );
continue;
}
}
if ( first )
first = false;
else
qualBuilder.addAttribQual( "AND" );
if ( attributeDef != null )
{
parseAttribute( qualEntityDef, attributeDef );
continue;
}
if ( childEntityDef != null )
{
token = jp.nextToken(); // Consume entity name.
parseEntity( qualEntityDef, childEntityDef );
continue;
}
switch ( fieldName.toLowerCase().trim() )
{
case "$or":
case "or":
parseList( qualEntityDef, entityDef, "OR" );
continue;
case "$and":
case "and":
parseList( qualEntityDef, entityDef, "AND" );
continue;
}
throw new ZeidonException( "Unknown field name in JSON string: %s", fieldName );
}
token = jp.nextToken(); // Skip past closing }.
return token;
}
private boolean parseBoolean( String paramName ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Consume "rootOnly".
if ( ! token.isScalarValue() )
throw new ZeidonException( "Expecting boolean for rootOnly value. Found %s", token );
boolean returnValue = false;
if ( token.asString().equals( "true" ) )
returnValue = true;
else
if ( ! token.asString().equals( "false" ) )
throw new ZeidonException( "Expecting boolean for rootOnly value. Found %s", token );
token = jp.nextToken(); // Consume boolean.
return returnValue;
}
private void parseRestricting() throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Consume "restricting".
if ( token != JsonToken.START_OBJECT )
throw new ZeidonException( "'Restricting' value doesn't start with object. Found %s", token );
token = jp.nextToken(); // Consume open '{'.
while ( ( token = jp.getCurrentToken() ) != JsonToken.END_OBJECT )
{
if ( token != JsonToken.FIELD_NAME )
throw new ZeidonException( "Unexpected token; expecting FIELD" );
String entityName = jp.getCurrentName();
EntityDef childEntityDef = qualBuilder.getLodDef().getEntityDef( entityName, false );
if ( childEntityDef == null )
throw new ZeidonException( "Field name in Restricting object is not an entity name: %s", entityName );
token = jp.nextToken(); // Consume entity name.
qualBuilder.forEntity( entityName );
parseEntity( childEntityDef, childEntityDef );
}
}
/**
* {
* pagination: {
* pageSize: 20,
* currentPage: 1,
* totalPages: 4,
* totalCount: 10
* }
* }
*
* @throws JsonParseException
* @throws IOException
*/
private void parsePagination() throws JsonParseException, IOException
{
Pagination page = new Pagination();
JsonToken token = jp.nextToken(); // Consume "pagination".
if ( token != JsonToken.START_OBJECT )
throw new ZeidonException( "'pagination' value doesn't start with object. Found %s", token );
token = jp.nextToken(); // Consume open '{'.
while ( ( token = jp.getCurrentToken() ) != JsonToken.END_OBJECT )
{
if ( token != JsonToken.FIELD_NAME )
throw new ZeidonException( "Unexpected token; expecting FIELD" );
String param = jp.getCurrentName();
token = jp.nextToken(); // Consume param name.
String value = jp.getValueAsString();
token = jp.nextToken(); // Consume value.
switch( param )
{
case "pageSize":
page.setPageSize( Integer.parseInt( value ) );
break;
case "totalPages":
break;
case "currentPage":
page.setPageNumber( Integer.parseInt( value ) );
break;
case "totalCount":
// If the value is null then we'll assume that the root count hasn't been
// loaded yet so set flag to calculate it.
if ( value == null )
page.setLoadTotalCount( true );
else
// The total has already been loaded and the client has told us what it is.
// Save it.
page.setTotalCount( Integer.parseInt( value ) );
break;
default:
throw new ZeidonException( "Unknown pagination param name '%s'", param );
}
}
token = jp.nextToken(); // Skip past closing }.
qualBuilder.setPagination( page );
}
/**
*
* Handles
{
$orderBy: "age"
$orderBy: { age: "desc" }
$orderBy: [ { age: "desc" }, { gender: "asc"} ]
}
*/
private void parseOrderBy(EntityDef qualEntityDef) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Consume "orderBy".
switch ( token )
{
case START_OBJECT:
parseOrderByObject( qualEntityDef );
break;
case START_ARRAY:
parseOrderByArray( qualEntityDef );
break;
case VALUE_STRING:
parseOrderByAttribute( qualEntityDef );
break;
default:
throw new ZeidonException( "orderBy: unexpected token %s", token );
}
}
/**
*
* Handles
{
$orderBy: [ { age: "desc" }, { gender: "asc"} ]
}
*/
private void parseOrderByArray( EntityDef orderEntityDef ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Consume start object.
while ( token != JsonToken.END_ARRAY )
{
// TODO: Some day it would be nice to handle [ "attr1", "attr2", ... ] but for now
// we only support a list of objects.
if ( token != JsonToken.START_OBJECT )
throw new ZeidonException( "Unexpected token; expecting FIELD" );
parseOrderByObject( orderEntityDef );
}
token = jp.nextToken(); // Skip past closing ].
}
/**
*
* Handles
{
$orderBy: "age"
}
*/
private void parseOrderByAttribute( EntityDef orderEntityDef ) throws JsonParseException, IOException
{
String attribName = jp.getValueAsString();
jp.nextToken(); // Consume value.
qualBuilder.addActivateOrdering( orderEntityDef.getName(), attribName, false );
}
/**
*
* Handles
{
$orderBy: { age: "desc" }
}
*/
private void parseOrderByObject( EntityDef orderEntityDef ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Consume start object.
if ( token != JsonToken.FIELD_NAME )
throw new ZeidonException( "Unexpected token; expecting FIELD" );
String attribName = jp.getCurrentName();
token = jp.nextToken(); // Consume name.
String value = jp.getValueAsString();
token = jp.nextToken(); // Consume value.
boolean descending = ! StringUtils.isBlank( value ) && value.toLowerCase().startsWith( "desc" );
qualBuilder.addActivateOrdering( orderEntityDef.getName(), attribName, descending );
token = jp.nextToken(); // Skip past closing }.
}
/**
*
* Parameter 'command' is the string used to invoke this object (e.g. "usingSql").
* Handles
{
$usingSql: {
sql: "select id, name from users where ....",
attributes: "Id, Name"
}
}
*/
private void parseOpenSql( String command, EntityDef qualEntityDef ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Consume "usingSql".
if ( token != JsonToken.START_OBJECT )
throw new ZeidonException( "%s: expecting '{' but got %s", command, token );
String sql = null;
String attrList = null;
token = jp.nextToken(); // Consume "{".
while ( token != JsonToken.END_OBJECT )
{
if ( token != JsonToken.FIELD_NAME )
throw new ZeidonException( "%s: Unexpected token; expecting FIELD but got %s", command, token );
String param = jp.getCurrentName();
token = jp.nextToken(); // Consume param name.
String value = jp.getValueAsString();
token = jp.nextToken(); // Consume value.
switch( param.toLowerCase() )
{
case "sql":
sql = value;
break;
case "attributes":
attrList = value;
break;
default:
throw new ZeidonException( "Unknown %s param name '%s'", command, param );
}
}
if ( StringUtils.isBlank( sql ) )
throw new ZeidonException( "%s: SQL string not set", command );
if ( StringUtils.isBlank( attrList ) )
throw new ZeidonException( "%s: Attributes list not set", command );
qualBuilder.setOpenSql( sql, attrList );
token = jp.nextToken(); // Skip past closing }.
}
private void parseAttribute( EntityDef qualEntityDef, AttributeDef attributeDef ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Move to attribute value.
if ( token.isScalarValue() )
{
String value = jp.getValueAsString();
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), "=", value );
token = jp.nextToken(); // Consume the attribute value.
return;
}
if ( token == JsonToken.START_ARRAY )
{
parseValueArray( attributeDef );
return;
}
if ( token == JsonToken.START_OBJECT )
{
parseOper( attributeDef );
return;
}
throw new ZeidonException( "Unexpected token found for attribute qualification: %s", token );
}
private void parseOper( AttributeDef attributeDef ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Skip past '{'.
if ( token != JsonToken.FIELD_NAME )
throw new ZeidonException( "Expecting field name for attribute operation. Got %s", token );
int count = 0;
while ( token == JsonToken.FIELD_NAME )
{
count++;
if ( count == 2 )
{
// We now know we have more than one oper so insert an opening paren.
qualBuilder.prependOpenParen();
}
if ( count > 1 )
qualBuilder.addAttribQual( "AND" );
String oper = jp.getCurrentName();
token = jp.nextToken(); // Skip past field name.
if ( ! token.isScalarValue() )
throw new ZeidonException( "Expecting scalar value for operation operand. Got %s", token );
String value = jp.getValueAsString();
token = jp.nextToken(); // Consume value.
switch ( oper.toLowerCase().trim() )
{
case "<":
case "$lt":
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), "<", value );
break;
case "<=":
case "$lte":
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), "<=", value );
break;
case ">":
case "$gt":
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), ">", value );
break;
case ">=":
case "$gte":
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), ">=", value );
break;
case "=":
case "==":
case "$eq":
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), "=", value );
break;
case "!=":
case "<>":
case "$neq":
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), "!=", value );
break;
default:
throw new ZeidonException( "Unknown operation %s", oper );
}
}
if ( count > 1 )
qualBuilder.addAttribQual( ")" );
if ( token != JsonToken.END_OBJECT )
throw new ZeidonException( "Expected '}'. Got %s", token );
token = jp.nextToken(); // Consume '}'
}
private void parseValueArray( AttributeDef attributeDef ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Move past start of array.
qualBuilder.addAttribQual( "(" );
boolean first = true;
while ( token != JsonToken.END_ARRAY )
{
if ( ! token.isScalarValue() )
throw new ZeidonException( "Expecting a scalar value inside attribute array. Got %s", token );
if ( first )
first = false;
else
qualBuilder.addAttribQual( "OR" );
String value = jp.getValueAsString();
qualBuilder.addAttribQual( attributeDef.getEntityDef().getName(), attributeDef.getName(), "=", value );
token = jp.nextToken();
}
qualBuilder.addAttribQual( ")" );
token = jp.nextToken(); // Consume ']'
}
private void parseList( EntityDef qualEntityDef, EntityDef entityDef, String conjunction ) throws JsonParseException, IOException
{
JsonToken token = jp.nextToken(); // Move past "$or/$and"
if ( token != JsonToken.START_ARRAY )
throw new ZeidonException( "Expecting start of array for '$or/and' clause. Got %s", token );
token = jp.nextToken(); // Move past "["
qualBuilder.addAttribQual( "(" );
boolean first = true;
while ( token != JsonToken.END_ARRAY )
{
if ( first )
first = false;
else
qualBuilder.addAttribQual( conjunction );
token = parseEntity( qualEntityDef, entityDef );
}
qualBuilder.addAttribQual( ")" );
jp.nextToken(); // Consume closing ']'
}
}
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