rx java - RxJava Zip with priorities -


here's problem. have number of async operations result gets aggregated single 1 further processed. however, not operations equal , error handling different based on operation fails.

to elaborate, let's have operations a, b , c. if fails, need end processing if b or c fail, continue processing others normal.

currently, achieve using count down latches , lot of state management taking close hundred lines of code. move rxjava based implementation. first thought trying observable.zip operator treats observables equals , not true in case. other idea chaining calls, works, means operations won't start @ same time resulting in greater overall time.

can guide me on how achieve this?

use .onerrorresumenext:

observable<t> a, b, c; observable.zip(     a,     b.onerrorresumenext(t -> observable.just(null)),     c.onerrorresumenext(t -> observable.just(null)),    (x, y, z) -> <your aggregation>) ...

representing errored observables null you. use optional:

observable.zip(     a,     b.map(x -> optional.of(x))      .onerrorresumenext(t -> observable.just(optional.empty())),     c.map(x -> optional.of(x))      .onerrorresumenext(t -> observable.just(optional.empty())),    (x, y, z) -> <your aggregation>)

if b , c correspond external service calls might want ignore them if take long replacing b b.timeout(5, timeunit.seconds). concise eh!


Comments

Post a Comment

Popular posts from this blog

jOOQ update returning clause with Oracle -

according http://www.jooq.org/doc/3.8/manual/sql-building/sql-statements/update-statement/ jooq doesn't support returning clause in update statements databases except firebird , postgres. does know, still correct oracle jooq? according oracle's documentation, oracle db supports returning clase delete, insert, or update statements. incorrect manual you're right - manual wrong , should fixed: https://github.com/jooq/jooq/issues/5470 single row update returning jooq 3.8 added support single row update .. returning statements. internally, uses callablestatement , pl/sql block of form: begin update "my_table" set "my_table"."column" = 'xyz' "my_table"."id" = 1 returning "my_table"."id", "my_table"."column" ?, ?; ? := sql%rowcount; end; the relevant issue is: https://github.com/jooq/jooq/issues/5190 multi row update returning a...
Read more

java - Warning equals/hashCode on @Data annotation lombok with inheritance -

i have entity inherits other. on other hand, i'm using lombok project reduce boilerplate code, put @data annotation. annotation @data inheritance produces next warning: generating equals/hashcode implementation without call superclass, though class not extend java.lang.object. if intentional, add '@equalsandhashcode(callsuper=false)' type. is advisable add annotation @equalsandhashcode (callsuper = true) or @equalsandhashcode (callsuper = false) ? if not added, 1 callsuper=false or callsuper=true ? the default value false . 1 if don't specify , ignore warning. yes, recommended add @equalsandhashcode annotation on @data annotated classes extend else object. cannot tell if need true or false , depends on class hierarchy, , need examined on case-by-case basis. however, project or package, can configure in lombok.config call super methods if not direct subclass of object. lombok.equalsandhashcode.callsuper = call for configuration system ...
Read more

java - BasicPathUsageException: Cannot join to attribute of basic type -

i using java 8 jpa (hibernate 5.2.1). have clause works perfectly, until introduce clause make use foreign key table values too. i getting following error: basicpathusageexception: cannot join attribute of basic type i think problem related fact have join table, , not sure how create join using join table. employee - employee_category - category model (employee.java): @manytomany(cascade = cascadetype.all, fetch=fetchtype.eager) @jointable ( name="employee_category", joincolumns={ @joincolumn(name="emp_id", referencedcolumnname="id") }, inversejoincolumns={ @joincolumn(name="cat_id", referencedcolumnname="id") } ) private set<category> categories; model (category.java): @id private string id; jpa when introduce following code, fails error above (i think problem new piece of code): join<t, category> category = from.join("id"); predicates.add(criteriabuilder.like(category....
Read more