增加jvisualVM OQL结果集的最大大小 [英] Increasing the max size of jvisualVM OQL resultset
问题描述
我有一个内存转储文件，它有近5000个特定对象的实例。这些对象将写入数据库，我这样做的方法是在jvisualvm中编写一个OQL查询以生成一个字符串，该字符串将用作SQL插入，例如
I have a memory dump file which has nearly 5000 instances of a particular object. These objects are to be written into a DB, and the way i am doing this is to write an OQL query in jvisualvm to generate a string that will serve as an SQL insert for example
select "insert into trades (id, tradeNumber) values ("+ x.id+ ", " + x.tradeNumber +");" from com.test.application.TradeObject x;
当我通过OQL运行时，我得到一个结果集如下 -
When i run this via OQL, i get a result set like this -
<code>
insert into trades (id, tradeNumber) values (1,12345);
insert into trades (id, tradeNumber) values (2,123456);
insert into trades (id, tradeNumber) values (3,123457); </code>
等
但是，因为总数实例数量很大（大约5000）JvisualVM只显示其中的大约100个。然后出现错误消息结果太多。请优化您的查询。
However, since the total number of instances is large (around 5000) JvisualVM only shows about 100 of them. and then errors out with a message "Too many results. Please, refine your query."
我无法优化查询，因为我必须以这种方式解析所有实例。
有没有办法可以让JvisualVM向我显示所有实例而不限制结果数量？
I cannot refine the query as i have to parse all instances this way. Is there a way in which i can ask JvisualVM to show me all instances and not restrict the number of results?
我还看到Jvisual vm显示前100个没有任何过滤器的实例，是否可以通过OQL查询获得接下来的100个实例等等？
I also see that Jvisual vm shows the first 100 instances without any filters, is it possible to get the next 100 instances and so on via OQL query?
谢谢
推荐答案
我在jvisualVm中找不到任何设置来增加尺寸结果集。可能是不可能的那种方式。
它看起来像Jvisualvm代码库中的硬编码限制。参考： http://visualvm.sourcearchive.com/documentation/1.3/OQLController_8java-source.html
I couldn't find any settings in jvisualVm to increase the size of resultset. May be its not possible that way. It looks like a hard coded limit in Jvisualvm code base. Ref: http://visualvm.sourcearchive.com/documentation/1.3/OQLController_8java-source.html
在那里找到以下片段：
final AtomicInteger counter = new AtomicInteger(100);
和
if (counter.get() == 0) {
sb.append("<tr><td><h4>Too many results. Please, refine your query.</h4></td></tr>" );
} else if (counter.get() == 100) {
sb.append("<tr><td><h4>"); // NOI18N
sb.append(NbBundle.getMessage(OQLController.class, "OQL_NO_RESULTS_MSG")); // NOI18N
sb.append("</h4></td></tr>" ); // NOI18N
}
现在是有趣的部分，解决您的问题。
Now the interesting part, the workaround for your problem.
考虑下面的课程：
package com.demo.test;
class Xyz {
int idXyz;// intentionally not set as id
String value;
public Xyz(int idXyz, String value) {
this.idXyz = idXyz;
this.value = value;
}
}
现在说我在这个班级的内存中有105个对象，保存在以下列表中：
now say I have 105 objects in memory for this class, kept in a list like :
static List<Xyz> lst = new ArrayList<>();
for (int i = 0; i < 105; i++) {
lst.add(new Xyz( i,"xyz value-" + i));
}
我需要实现您的目标。
现在要显示这105个对象而不是列出所有结果集，我宁愿遍历所有对象并创建一个包含由新行分隔的所有SQL查询的单个字符串。为此，您需要在查询编辑器中调用类似的OQL脚本。
Now to show these 105 objects instead of listing all the result sets, i would rather iterate over all the objects and create one single string containing all the SQL queries separated by new line. For this you need to invoke similar OQL script in Query Editor.
function fun(objEnumeration){
var res =" ";
while (objEnumeration.hasMoreElements()) {
var itr = objEnumeration.nextElement();
var v = "insert into table_Xyz (idXyz, value) values ("+ itr.idXyz.toString()+ ", " + itr.value.toString() +");\n"
res = res + v;
}
return res;
}
fun(heap.objects("com.demo.test.Xyz"));
以及查询结果标签中的结果be：
and the result in Query Results tab will be:
insert into table_Xyz (idXyz, value) values (104, xyz value-104);
insert into table_Xyz (idXyz, value) values (103, xyz value-103);
insert into table_Xyz (idXyz, value) values (102, xyz value-102);
insert into table_Xyz (idXyz, value) values (101, xyz value-101);
insert into table_Xyz (idXyz, value) values (100, xyz value-100);
insert into table_Xyz (idXyz, value) values (99, xyz value-99);
insert into table_Xyz (idXyz, value) values (98, xyz value-98);
insert into table_Xyz (idXyz, value) values (97, xyz value-97);
insert into table_Xyz (idXyz, value) values (96, xyz value-96);
insert into table_Xyz (idXyz, value) values (95, xyz value-95);
insert into table_Xyz (idXyz, value) values (94, xyz value-94);
insert into table_Xyz (idXyz, value) values (93, xyz value-93);
insert into table_Xyz (idXyz, value) values (92, xyz value-92);
insert into table_Xyz (idXyz, value) values (91, xyz value-91);
insert into table_Xyz (idXyz, value) values (90, xyz value-90);
insert into table_Xyz (idXyz, value) values (89, xyz value-89);
insert into table_Xyz (idXyz, value) values (88, xyz value-88);
insert into table_Xyz (idXyz, value) values (87, xyz value-87);
insert into table_Xyz (idXyz, value) values (86, xyz value-86);
insert into table_Xyz (idXyz, value) values (85, xyz value-85);
insert into table_Xyz (idXyz, value) values (84, xyz value-84);
insert into table_Xyz (idXyz, value) values (83, xyz value-83);
insert into table_Xyz (idXyz, value) values (82, xyz value-82);
insert into table_Xyz (idXyz, value) values (81, xyz value-81);
insert into table_Xyz (idXyz, value) values (80, xyz value-80);
insert into table_Xyz (idXyz, value) values (79, xyz value-79);
insert into table_Xyz (idXyz, value) values (78, xyz value-78);
insert into table_Xyz (idXyz, value) values (77, xyz value-77);
insert into table_Xyz (idXyz, value) values (76, xyz value-76);
insert into table_Xyz (idXyz, value) values (75, xyz value-75);
insert into table_Xyz (idXyz, value) values (74, xyz value-74);
insert into table_Xyz (idXyz, value) values (73, xyz value-73);
insert into table_Xyz (idXyz, value) values (72, xyz value-72);
insert into table_Xyz (idXyz, value) values (71, xyz value-71);
insert into table_Xyz (idXyz, value) values (70, xyz value-70);
insert into table_Xyz (idXyz, value) values (69, xyz value-69);
insert into table_Xyz (idXyz, value) values (68, xyz value-68);
insert into table_Xyz (idXyz, value) values (67, xyz value-67);
insert into table_Xyz (idXyz, value) values (66, xyz value-66);
insert into table_Xyz (idXyz, value) values (65, xyz value-65);
insert into table_Xyz (idXyz, value) values (64, xyz value-64);
insert into table_Xyz (idXyz, value) values (63, xyz value-63);
insert into table_Xyz (idXyz, value) values (62, xyz value-62);
insert into table_Xyz (idXyz, value) values (61, xyz value-61);
insert into table_Xyz (idXyz, value) values (60, xyz value-60);
insert into table_Xyz (idXyz, value) values (59, xyz value-59);
insert into table_Xyz (idXyz, value) values (58, xyz value-58);
insert into table_Xyz (idXyz, value) values (57, xyz value-57);
insert into table_Xyz (idXyz, value) values (56, xyz value-56);
insert into table_Xyz (idXyz, value) values (55, xyz value-55);
insert into table_Xyz (idXyz, value) values (54, xyz value-54);
insert into table_Xyz (idXyz, value) values (53, xyz value-53);
insert into table_Xyz (idXyz, value) values (52, xyz value-52);
insert into table_Xyz (idXyz, value) values (51, xyz value-51);
insert into table_Xyz (idXyz, value) values (50, xyz value-50);
insert into table_Xyz (idXyz, value) values (49, xyz value-49);
insert into table_Xyz (idXyz, value) values (48, xyz value-48);
insert into table_Xyz (idXyz, value) values (47, xyz value-47);
insert into table_Xyz (idXyz, value) values (46, xyz value-46);
insert into table_Xyz (idXyz, value) values (45, xyz value-45);
insert into table_Xyz (idXyz, value) values (44, xyz value-44);
insert into table_Xyz (idXyz, value) values (43, xyz value-43);
insert into table_Xyz (idXyz, value) values (42, xyz value-42);
insert into table_Xyz (idXyz, value) values (41, xyz value-41);
insert into table_Xyz (idXyz, value) values (40, xyz value-40);
insert into table_Xyz (idXyz, value) values (39, xyz value-39);
insert into table_Xyz (idXyz, value) values (38, xyz value-38);
insert into table_Xyz (idXyz, value) values (37, xyz value-37);
insert into table_Xyz (idXyz, value) values (36, xyz value-36);
insert into table_Xyz (idXyz, value) values (35, xyz value-35);
insert into table_Xyz (idXyz, value) values (34, xyz value-34);
insert into table_Xyz (idXyz, value) values (33, xyz value-33);
insert into table_Xyz (idXyz, value) values (32, xyz value-32);
insert into table_Xyz (idXyz, value) values (31, xyz value-31);
insert into table_Xyz (idXyz, value) values (30, xyz value-30);
insert into table_Xyz (idXyz, value) values (29, xyz value-29);
insert into table_Xyz (idXyz, value) values (28, xyz value-28);
insert into table_Xyz (idXyz, value) values (27, xyz value-27);
insert into table_Xyz (idXyz, value) values (26, xyz value-26);
insert into table_Xyz (idXyz, value) values (25, xyz value-25);
insert into table_Xyz (idXyz, value) values (24, xyz value-24);
insert into table_Xyz (idXyz, value) values (23, xyz value-23);
insert into table_Xyz (idXyz, value) values (22, xyz value-22);
insert into table_Xyz (idXyz, value) values (21, xyz value-21);
insert into table_Xyz (idXyz, value) values (20, xyz value-20);
insert into table_Xyz (idXyz, value) values (19, xyz value-19);
insert into table_Xyz (idXyz, value) values (18, xyz value-18);
insert into table_Xyz (idXyz, value) values (17, xyz value-17);
insert into table_Xyz (idXyz, value) values (16, xyz value-16);
insert into table_Xyz (idXyz, value) values (15, xyz value-15);
insert into table_Xyz (idXyz, value) values (14, xyz value-14);
insert into table_Xyz (idXyz, value) values (13, xyz value-13);
insert into table_Xyz (idXyz, value) values (12, xyz value-12);
insert into table_Xyz (idXyz, value) values (11, xyz value-11);
insert into table_Xyz (idXyz, value) values (10, xyz value-10);
insert into table_Xyz (idXyz, value) values (9, xyz value-9);
insert into table_Xyz (idXyz, value) values (8, xyz value-8);
insert into table_Xyz (idXyz, value) values (7, xyz value-7);
insert into table_Xyz (idXyz, value) values (6, xyz value-6);
insert into table_Xyz (idXyz, value) values (5, xyz value-5);
insert into table_Xyz (idXyz, value) values (4, xyz value-4);
insert into table_Xyz (idXyz, value) values (3, xyz value-3);
insert into table_Xyz (idXyz, value) values (2, xyz value-2);
insert into table_Xyz (idXyz, value) values (1, xyz value-1);
insert into table_Xyz (idXyz, value) values (0, xyz value-0);
只需修改OQL脚本以满足您的要求。
just modify the OQL script to suit your requirement.
注意：在类Xyz中，字段idXyz是故意不设置为id ，因为在这种情况下 itr.id 将返回与该实例关联的对象ID。
NOTE: in class Xyz the field idXyz was intentionally not set as id, as in that case itr.id will return object id associated with that instance.
有关OQL方法的更多内容参考： http://visualvm.java.net/oqlhelp.html#toHtml
for more on OQL methods ref: http://visualvm.java.net/oqlhelp.html#toHtml
这篇关于增加jvisualVM OQL结果集的最大大小的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
