Poland's military leader, Gen. Wojciech Jaruzelski, today received what was portrayed as a hero's welcome in East Germany, one of the Soviet Bloc countries that had been most critical of Poland's 18 months of liberalization.

The official East German news agency ADN reported that the warm reception for Jaruzelski was combined with a strong endorsement of the martial-law restrictions he imposed in Poland last December. The visit marked a formal return to good relations between the two Communist neighbors.

The Polish leader was met at the airport by East German Communist Party secretary Erich Honecker, ADN reported. He was given a full honor guard of goose-stepping soldiers to review and--as when he went to Moscow last month--the streets leading to the center of the city were filled with crowds waving red and white Polish flags.

The effusive welcome was designed to show the outside world that the Polish leadership can count on East German political and economic support after averting what Soviet Bloc officials called "the threat of counterrevolution." ADN described talks between Honecker and Jaruzelski as having taken place in "a friendly atmosphere" with "full agreement on all questions discussed."

This emphasis on unanimity of views contrasted with last year when the East Germans repeatedly urged Poland's leadership to take tougher measures against the independent Solidarity trade union. Polish tourist traffic to East Germany was cut to a trickle and bilateral trade also fell.

Since the crackdown, East Germany has pledged to provide greater economic assistance to Poland. Intensive publicity was given to a long convoy of trucks that arrived in Warsaw shortly after the declaration of martial law with gifts of food and clothing.

Many of the parcels had been put together by children and some contained reproving messages such as: "My father works and we have everything. Your father strikes and you have nothing."

Faced with a freeze on Western financial credits, Polish officials have said they intend to turn to their Communist allies for desperately needed imports of spare parts and raw materials, without which many factories are grinding to a halt. The impression among Western diplomats here, however, is that there is a limit to both Soviet Bloc generosity and Poland's ability to revive its industry within a short period of time without Western help.

Jaruzelski's trip to East Germany, only his second foreign visit since December, comes at a time when he appears to be trying to consolidate his political position at home. A gradually hardening domestic line over the past few weeks was reflected in the abolition of the professional journalists' association and continued stiff sentences for Solidarity leaders accused of organizing strikes.

A new, party-controlled journalists' association has been launched and it has pledged to make a clean break with the policies of the former association that were seen as overly sympathetic to Solidarity. At a press conference today, the new association's chairman, Klemens Krzyzagorski, said that at least 21 Polish newspapers and magazines would close permanently as a result of martial law.

Meanwhile, a former deputy prime minister, Franciszek Kaim, was sentenced to a year's imprisonment and a fine of 300,000 zloties (nearly $4,000) on corruption charges. He was found guilty of giving his secretary five coupons for the priority purchase of cars, a valuable black market commodity.